FPS dropping every minute

Ok so apparently the help & support board is archived and I can't post there so im typing this here.

Today in the morning I had a nice 80 fps in game. I got home from work, then watched some streamers and now I have been currently stuck on the defeat screen for 14 minutes and counting. Can't task manager or alt f4 it.

I started the game with 50 fps and a little bit of stuttering and those only got worse every minute. In the last seconds I could count how many times my champion moved per second, and it got to 2-3 per sec, fps was at 14.

My laptop is 3 years old and never had problems before. Has anyone else had this problem recently or is it a problem with my laptop?

I was just about to get in D2 promos too :( I am now too afraid to que again if my laptop is broken.