My game is constantly crashing.

So to start this off i don't have the best computer and thats just a fact. I use for all of my school work and gaming on my mac which runs off the most recent Sierra OS. The thing is that i play a ton of games with little to no problems especially mobas. My current issue is that about 2 weeks ago my games started to just crash while i was in the loading screen. In the past i've had other problems like when i open the client it just doesn't respond and i'd have to redownload the game or just go into the package contents and delete the lockfile which works perfectly fine and stopped doing so about a month and a half ago after the the patch were kai'sa came out. But now since then anywhere from 1-5ish times a day my game will just crash. Which is very annoying cause i'm getting constantly reported and getting leaver penalties. I just don't know what to do i usually only have discord or maybe (very rarely) spotify. At this point i'm stuck and would like some help and or an explanation.