FPS drops to 5-10fps after one game

Hello all, feel like throwing my laptop out of the window because of this issue.

When I start the game up, I can play ONE game before the FPS drops for absolutely no reason at all to 5-10fps after playing 100-110fps. I have tried many different combinations of settings and turning v sync off and all of the other suggested fixes from other players that are floating around on the internet. Please can you sort this issue as my only solution currently is to play one match, restart the game to play another match, rinse and repeat. This is unacceptable. 

Please sort this issue or provide a fix or a settings config that will actually make it work.