Garry's Mod CTDing repeatedly since about six months back

Long story short, six months ago Garry’s Mod started CTDing while playing multiplayer, any gamemode, any map, any server. After trying everything I could think of, I got fed up and gave up for a few months, only to try again.
It didn’t work that time either, and I tried again just a few days ago. I just can’t figure out what’s wrong.
When I join a server, within 30 minutes the game crashes to desktop with a “hl2.exe has stopped working” message, without fail. Any server, any gamemode, any time. Singleplayer works fine. Other source engine games work fine, so it’s only Gmod.

Things I can remember trying;
Playing with in-game settings, ie turn multicore rendering off, etc
Verifying integrity of game cache
Updating and downgrading graphics card drivers
Running in windowed mode
Uninstalling Garry’s Mod completely (And I mean -completely-, including manual cleanup of files and registry) and reinstalling it all again
Not mounting any other games
Searching for software incompatibilities
Stresstest hardware for faults
Disable all addons

The only thing I can think of that I haven’t tried yet is to completely reinstall Win7, but I’m not sure if I wanna go through the trouble just for one game.
Until I change my mind, I have completely ran out of ideas the past months.

Oh I can’t read. I had something like this once but in singleplayer, getting rid of most complicated addons did the trick. As for your problem, wait for the next gmod patch and use singleplayer for the time being as the patch will be out soon I think.

I’ve finally, after trying dozens of gamemodes, found a few that don’t crash. Specifically TTT and everything that has to do with Gmod Tower. So far the only common thread I can find with the gamemodes that -do- crash are that they’re heavily physics based, ie slope, smash, sledbuild, that sort of thing.

Could this mean anything?