Basically the title.. Never had any similar problem in the past.
Felt like giving it another playthrough, downloaded it yesterday from EA platform, downloaded a few mods, tested them out until char creation, worked fine and went to bed because it was late and wanted to start today.
Boom. Infinite loading screen/not responding. Tried running it with admin and it just gives a "couldn't start game" error. Ran it without mods/Frosty, still nothing. Ran it with frosty, same thing and frosty gets stuck at "Waiting for game". Repaired, nothing. It always starts windowed if that's of any help. Other times it reaches my cpu usage to literally 100% even though my specs can deal with much more demand
