This just recently happened. It didnt happen before. Some days ago when i tried to play singleplayer something shitty happened. When im in game (multiplayer or singleplayer) the game just freezes. It just stops. THere is no error message or anything. I manage to play for 8 seconds. THen it freezes. My specs is good enough. Ive tried to reinstall gmod but it just happens again. Anyone have a solution?
Edit: Never mind. The problem is fixed. Had to reinstall entire steam.
Yeah, this kind of thing happens to me all the time. I like to install addons. A lot. Some of them hit errors in code, or GMod could be trying to load something that isn’t right. What happens to me is that the game freezes, and the health/ammo boxes go dark black instead of that semi-transparent gray that they usually are. I can still open the Esc. menu, though. Try removing any recently installed addons (it sucks, I know. I had to get rid of one that I really liked before.)
If you can still open the Esc. menu (or the console), then GMod is frozen and the issue is most likely what I’ve stated above. If your entire computer is frozen, then you have a bigger issue than GMod. If the latter is the case, I recommend updating your graphics card driver, and even try getting an updated version of DirectX from Microsoft. I had do this as well, as my unstable piece of crap likes to BSoD on me.
It didnt work to delete addons 
But thanks anyway 
It was worth the try.