Kkslr

So i just recently got Arma 2 and after about 10-20 minutes of gameplay the game becomes UNPLAYABLE :( by unplayable i mean around 1-5 fps and grafical glitches everywhere objects becoming invisible and reappearing ect. i have uninstalled and reinstalled the game and it did not help. i have no idea how to fix this and i would appreciate some help. because the small amount of time ive spent on the game have been amazing and i really dont want to have waisted my money on a game i cannot play for more than 20 minutes at a time withought having to close and restart the game. the issues still remain in the start menu as well. I might also add when im playing multiplayer and this issue occurs when i go back to the server list all the servers go to 500-2000 even 3000 ping.