Hello mate, long time!
But you must've played it reasonably well at some point to be 'fifth horseman of the apocalypse' (old joke that most people won't remember)!
Sorry to hear you're having problems, have you moved over to the TF mods yet?
Make sure you've done all the old tricks, such as clearing out the cache of old shaders and things, and make sure you don't have any other programs running that you don't need. Flash player particularly tends to crash the game.