Here's my crash log:

---- Minecraft Crash Report ----
// Sorry :(

Time: 2/27/18 10:12 PM
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
at bsa.n(SourceFile:296)
at bsa.e(SourceFile:275)
at bib.t(SourceFile:1602)
at bib.az(SourceFile:1000)
at bib.a(SourceFile:419)
at net.minecraft.client.main.Main.main(SourceFile:123)


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

-- Head --
Thread: Client thread
Stacktrace:
at bsa.n(SourceFile:296)
at bsa.e(SourceFile:275)

-- Affected level --
Details:
Level name: MpServer
All players: 0 total; []
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options:
Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 0 game time, 0 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 0 total; []
Retry entities: 0 total; []
Server brand: ~~ERROR~~ NullPointerException: null
Server type: Non-integrated multiplayer server
Stacktrace:
at bsb.a(SourceFile:366)
at bib.b(SourceFile:2587)
at bib.a(SourceFile:433)
at net.minecraft.client.main.Main.main(SourceFile:123)

-- System Details --
Details:
Minecraft Version: 1.12.2
Operating System: Windows 10 (x86) version 10.0
Java Version: 1.8.0_161, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 115835072 bytes (110 MB) / 201326592 bytes (192 MB) up to 1073741824 bytes (1024 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.12.2
LWJGL: 2.9.4
OpenGL: GeForce GTX 1060/PCIe/SSE2 GL version 4.6.0 NVIDIA 388.31, NVIDIA Corporation
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

Using VBOs: Yes
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: English (US)
Profiler Position: N/A (disabled)
CPU: 8x Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz




(by the way, this just started happening a few days ago, before that minecraft worked perfectly fine on my computer)