Game crashing and freezing

My game randomly crashes when I'm in the middle of a game and I have to restart my computer to get it to work and by that point, the games lost and I get reported for being AFK. I thought it only happened while I was playing with people, but I was just soloqing as Senna and it happened again and this time, reloading the game crashed it again. I don't know what I can do to fix it but it puts me behind and I would prefer not to be banned because of something I can't control. I've been playing League since last season (slightly before the God King event) and haven't had this issue until a few months ago. I've tried the troubleshooter and I've uninstalled it and reinstalled it and the issue persists.