I found how to fix the new Garry’s Mod update! If you go to the game folder(garrysmod) and then you press the organize button and then properties, you can restore to older versions! restore to a version saved a week ago or so, and you should be good! (It kinda takes a long time, but its worth it![If you want it to go faster, restore only like 7 files at a time])
OS>Program Files>Steam>Steamapps>Your Name Here>Garrysmod
Restore that one.