My add-ons will not load correctly

So, this has been going on for a while with my gmod, maybe about a month now. At first I was experiencing errors with missing textures on Half Life 2 things so I completely uninstalled the game and I think it screwed it up, now my Gmod will not load all of my add-ons and also keeps trying to download a workshop item on steam that has 0 bytes and it sits there trying to download something not there, any help?