Minecraft keeps freezing when loading a world... help

Check the settings and possibly move the chunk rendering to 2

We need a bit more information than this to be able to assist you.

When does it freeze, what happens after it's frozen (does the game stop responding?)

Could you attach a launcher_log also: First open your .minecraft folder (!?f platform/.minecraft), then try to
launch the game. Then in the .minecraft folder open the launcher_log
file, and copy its content to https://paste.ubuntu.com Click "Paste!", then share with us the link (the URL) that it takes you to.