mac client doesn't work properly [CRASH]

Since the 4.17 update, i have gotten a LOT of crashes and ping issues. i thought that they fixed it in the 4.18 patch but it's the same problem. In the loading screen i ping 50-60 then when i get in game i start pinging 300-1500 and then i crash. my macbook is capable of running other games like dota and stuff with super low ping and high fps but when i try to play league of legends i start to ping and crash. Im just very upset because i have spent a lot of time (i played 5-6 games a day or even more before this issue) and money on this game and i hope riot makes a fix soon.