Gmod is so laggy even tought i deleted all my mods and in addon folder

[T-Virus]

Hello community i hope somone knows how to fix this. Since yesterday my gmod whit 1400 hours of playtime is very laggy when i go on servers! i even reseted everything and deleted all addons . My problem is if i try to join a server the picture wont load and i cant join a server because it takes to long and it says you timed out every time if i go in a server whit many addons. and if i go in a server whit not many addons and very much players it lags. i tryd to watch some fps fix videos but they didnt help i RESTEDED EVRYTHING in gmod whit this one file but it doesnt change anything but it starts faster now wow thats not what i need .
Pls help i will appricate it since it is my favorite game

[MrKuBu]

Try to reinstall the game and change the graphics

[mcNuggets]

Delete all local files first and then re-install.