Help? Game Freezes And Crashes Only A Few Minutes Into My Games!

I don't know what exactly has been going on, but this problem has been plaguing my account for almost half a year now. On occasion, when I go into a game, everything just hard freezes at around the 1-2 minute mark. My audio cuts, and I can't even Alt + Tab out of the game screen. If I turn my laptop off and on, I can normally get back into the game late and continue normally, if I'm lucky. My connection is fine so that's not the issue, and I just did a full uninstallation and reinstallation of League about a month ago, so I don't know what the source of the problem could be! Season 9 was the season I was really going to buckle down and play and climb, but if I keep coming into games 5 minutes late, or keep getting leavebusters (which kinda sucks; Riot should be able to tell the difference between leaving a game and a game crashing) I don't think the drive is going to last.

Does anyone else have this problem? Does anyone know where I could talk to someone in support? I would like to end this once and for all.