Screwed up textures

So now since I downloaded a few addons for no reason this happened when I got on GMod today.

Why didn’t this happen before? What is even going on?
It’s mostly foilage that’s having these issues. Anybody willing to help me fix this? I really hope I don’t have to reinstall my whole GMod.

EDIT: Shit, I posted this in the wrong subforum. If this can be moved that’d be nice…