League of Legends mometery screen freezing

So I really love league so this problem is really bugging me I have good graphic card and solid net and my ms are ok too but for some reason whenever there is teamfight or some champion gets too close to mine my screen freezes from 1 to 3 seconds and this is really troubling me because I have to limit my champion roster and cant play anyone who is melee otherwise I cant enjyo the game I tryed reinstalling and doing the bug repair everything please help Thank you <3