Leaver buster

My computer has started going black and i can't see anything and sometimes last 1 - 20 minutes, but ill join match again and sometimes ill still win. Every time i leave a game is because of this thing that been happening and after i win the match or lose i go back to play another match, but leaver buster says i have to wait 20 minutes to join next lobby 5 times, so i have to play a game then wait 20 mins before getting into the next one and every time my computer does this it forces me to shut down my computer and reconnect to my game, and i can't help it.