While loading everything is fine, but when I want to create or join a World my Minecraft goes into a frozen state, althought I didn't even touch the configs, I looked at them but couldn't figure out what is causing it.

Log:

https://pastebin.com/U7zLt6AC

I'm sorry you're having an issue. However, I don't see what's wrong immediately, and I no longer support 1.7.10. The best you can do is try the beta 2.x.x versions and see if they work.