Game freezes when launching game

I lost lp from 2 ranked matches because the game disconnects at the loading screen. The game would partly load then freeze. The only way to close it thereafter is to use task manager. This problem has been happening on and off for a while and I don't know what to do about it. This is making playing the game very difficult. The client prompted me to submit an error report, which I did, but I am still down LP with AFK penalties. This is the directory: C:\Users\Ayman\AppData\Local\Temp\PKM9628.tmp