MAC HIGH SIERRA CRASH

Every time i try to play the game it crashes and bugs-plats, it's to the point where I am losing every game because I am behind in farm, level, and kill. I am getting so frustrated with this. Riot please do something to support your mac players, I have invested a lot of time and money into this game and this is not the end result I wanted. I have to uninstall the game, and reinstall just to play 1-2 games before the problem occurs. The hextech repair tool does absolutely nothing. The in game league repair tool does nothing. I enjoy this game but it looks like I have to stop all together because I can't play.