As said in the summary I typed above, "Once I open the launcher, an Error 408 Request Time-out appears and when I try to get into my single player world, the game crashes," and that's it.

I have no idea what I did wrong, I had left the game alone for about 2 months since I was busy and had no time, and when I decided I wanted to get back to playing, this error showed up.

I did try to uninstall and reinstall twice and it worked the first time, but not the second after it eventually reverted to the same problem.

I have added the latest crash report in case it can be of any assistance. Thank you.