Single Player won't load

Every time I try to load single player it says "Saving World" before crashing and sending me back to the launcher.
I was playing it normally the last few days, I've tried increasing RAM. but I don't play online servers and bar a couple of mods, my worlds aren't overly big in terms of loaded chunks. It's making me tear my hair out.


This is the crash report


---- Minecraft Crash Report ----
// Shall we play a game?

Time: 03/05/20 06:01
Description: mouseClicked event handler

java.lang.OutOfMemoryError: Java heap space
at java.util.ArrayList.<init>(ArrayList.java:152) ~[?:1.8.0_51] {}
at com.google.common.collect.Lists.newArrayListWithCapacity(Lists.java:190) ~[guava-21.0.jar:?] {}
at net.minecraft.nbt.ListNBT$1.func_225649_b_(SourceFile:46) ~[?:?] {re:classloading}
at net.minecraft.nbt.ListNBT$1.func_225649_b_(SourceFile:31) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.func_229680_b_(CompoundNBT.java:425) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.access$200(CompoundNBT.java:27) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:43) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:30) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.func_229680_b_(CompoundNBT.java:425) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.access$200(CompoundNBT.java:27) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:43) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:30) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.func_229680_b_(CompoundNBT.java:425) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.access$200(CompoundNBT.java:27) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:43) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:30) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.func_229680_b_(CompoundNBT.java:425) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT.access$200(CompoundNBT.java:27) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:43) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompoundNBT$1.func_225649_b_(CompoundNBT.java:30) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompressedStreamTools.func_152455_a(CompressedStreamTools.java:121) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompressedStreamTools.func_152456_a(CompressedStreamTools.java:91) ~[?:?] {re:classloading}
at net.minecraft.nbt.CompressedStreamTools.func_74796_a(CompressedStreamTools.java:26) ~[?:?] {re:classloading}
at net.minecraft.world.storage.SaveFormat.getWorldData(SaveFormat.java:147) ~[?:?] {re:classloading}
at net.minecraft.world.storage.SaveFormat.func_215780_a(SaveFormat.java:141) ~[?:?] {re:classloading}
at net.minecraft.world.storage.SaveFormat.func_215779_a(SaveFormat.java:128) ~[?:?] {re:classloading}
at net.minecraft.world.storage.SaveFormat.func_75803_c(SaveFormat.java:117) ~[?:?] {re:classloading}
at net.minecraft.world.storage.SaveFormat.func_75799_b(SaveFormat.java:76) ~[?:?] {re:classloading}
at net.minecraft.client.gui.screen.WorldSelectionList.func_212330_a(SourceFile:74) ~[?:?] {re:classloading}
at net.minecraft.client.gui.screen.WorldSelectionList.<init>(SourceFile:66) ~[?:?] {re:classloading}
at net.minecraft.client.gui.screen.WorldSelectionScreen.init(SourceFile:46) ~[?:?] {re:classloading}
at net.minecraft.client.gui.screen.Screen.init(Screen.java:339) ~[?:?] {re:classloading,pl:runtimedistcleaner:A}


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Render thread
Stacktrace:
at java.util.ArrayList.<init>(ArrayList.java:152)
at com.google.common.collect.Lists.newArrayListWithCapacity(Lists.java:190)
at net.minecraft.nbt.ListNBT$1.func_225649_b_(SourceFile:46)
at net.minecraft.nbt.ListNBT$1.func_225649_b_(SourceFile:31)
at net.minecraft.nbt.CompoundNBT.func_229680_b_(CompoundNBT.java:425)
at net.minecraft.nbt.CompoundNBT.access$200(CompoundNBT.java:27)

-- Affected screen --
Details:
Screen name: net.minecraft.client.gui.screen.MainMenuScreen
Stacktrace:
at net.minecraft.client.gui.screen.Screen.wrapScreenError(Screen.java:449)
at net.minecraft.client.MouseHelper.func_198023_a(MouseHelper.java:80)
at net.minecraft.client.MouseHelper.lambda$null$4(MouseHelper.java:163)
at net.minecraft.client.MouseHelper$$Lambda$6139/998665853.run(Unknown Source)
at net.minecraft.util.concurrent.ThreadTaskExecutor.execute(SourceFile:94)
at net.minecraft.client.MouseHelper.lambda$registerCallbacks$5(MouseHelper.java:162)
at net.minecraft.client.MouseHelper$$Lambda$5409/1564476238.invoke(Unknown Source)
at org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:36)
at org.lwjgl.system.JNI.invokeV(Native Method)
at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3101)
at com.mojang.blaze3d.systems.RenderSystem.flipFrame(SourceFile:105)
at net.minecraft.client.MainWindow.func_227802_e_(SourceFile:301)
at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:947)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:554)
at net.minecraft.client.main.Main.main(SourceFile:204)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:56)
at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$420/1007402143.call(Unknown Source)
at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54)
at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72)
at cpw.mods.modlauncher.Launcher.run(Launcher.java:81)
at cpw.mods.modlauncher.Launcher.main(Launcher.java:65)

-- System Details --
Details:
Minecraft Version: 1.15.2
Minecraft Version ID: 1.15.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1526418520 bytes (1455 MB) / 2181038080 bytes (2080 MB) up to 4294967296 bytes (4096 MB)
CPUs: 4
JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx4G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
ModLauncher: 5.0.0-milestone.4+67+b1a340b
ModLauncher launch target: fmlclient
ModLauncher naming: srg
ModLauncher services:
/eventbus-2.0.0-milestone.1-service.jar eventbus PLUGINSERVICE
/forge-1.15.2-31.1.0.jar object_holder_definalize PLUGINSERVICE
/forge-1.15.2-31.1.0.jar runtime_enum_extender PLUGINSERVICE
/accesstransformers-2.0.0-milestone.1-shadowed.jar accesstransformer PLUGINSERVICE
/forge-1.15.2-31.1.0.jar capability_inject_definalize PLUGINSERVICE
/forge-1.15.2-31.1.0.jar runtimedistcleaner PLUGINSERVICE
/forge-1.15.2-31.1.0.jar fml TRANSFORMATIONSERVICE
FML: 31.1
Forge: net.minecraftforge:31.1.0
FML Language Providers:
javafml@31.1
minecraft@1
Mod List:
forge-1.15.2-31.1.0-client.jar Minecraft {minecraft@1.15.2 DONE}
delicateanddainty-0.1.1.jar Delicate and Dainty! {delicateanddainty@.1 DONE}
themidnight-0.5.7-3.jar The Midnight {midnight@0.5.7-3 DONE}
decorative_blocks-6d.jar Decorative Blocks {decorative_blocks@1.6 DONE}
obfuscate-0.4.2-1.15.2.jar Obfuscate {obfuscate@0.4.2 DONE}
embellishcraft-1.15.2-2.2.0.0.jar EmbellishCraft {embellishcraft@1.15.2-2.2.0.0 DONE}
worldedit-forge-mc1.15.2-7.1.0.jar WorldEdit {worldedit@7.1.0;48cc31c DONE}
BiomesOPlenty-1.15.2-10.0.0.345-universal.jar Biomes O' Plenty {biomesoplenty@1.15.2-10.0.0.342 DONE}
furniture-7.0.0-pre16-1.15.1.jar MrCrayfish's Furniture Mod {cfm@7.0.0-pre16 DONE}
mapperbase-1.15.2-1.1.0.0.jar Mapper Base {mapperbase@1.15.2-1.1.0.0 DONE}
vehicle-mod-0.43.5-1.15.2.jar MrCrayfish's Vehicle Mod {vehicle@0.43.5 DONE}
jei-1.15.2-6.0.0.4.jar Just Enough Items {jei@6.0.0.4 DONE}
Teletubbies-1.15.2-6.0.2.jar Teletubbies {teletubbies@6.0.2 DONE}
ChineseWorkshop-1.15.2-2.4.4.jar ChineseWorkshop {chineseworkshop@2.4.4 DONE}
Kiwi-1.15.2-2.6.5.jar Kiwi {kiwi@2.6.5 DONE}
forge-1.15.2-31.1.0-universal.jar Forge {forge@31.1.0 DONE}
paintings-1.15.2-7.0.0.0.jar Paintings ++ {paintings@1.14.4-6.0.1.5 DONE}
AutoRegLib-1.5-40.jar AutoRegLib {autoreglib@1.5-40 DONE}
Quark-r2.1-235.jar Quark {quark@r2.1-235 DONE}
Kiwi Modules:
chineseworkshop:blocks
chineseworkshop:debug_stick
chineseworkshop:decorations
chineseworkshop:materials
chineseworkshop:retexture
kiwi:contributors
Launched Version: 1.15.2-forge-31.1.0
Backend library: LWJGL version 3.2.2 build 10
Backend API: Intel(R) HD Graphics 4400 GL version 4.3.0 - Build 20.19.15.4642, Intel
GL Caps: Using framebuffer using OpenGL 3.0
Using VBOs: Yes
Is Modded: Definitely; Client brand changed to 'forge'
Type: Client (map_client.txt)
Resource Packs: vanilla, programer_art
Current Language: English (US)
CPU: 4x Intel(R) Core(TM) i7-4510U CPU @ 2.00GHz