Low FPS Problem

When the match starts everything is normal and I get around 100–120 FPS, but in the second half it suddenly drops to 5 FPS. Sometimes it even drops to 5 FPS right when some matches start. I’m honestly fed up — I’ve been playing this game for years and I love it, but this issue is really starting to annoy me.

Please fix this issue already. I’m not enjoying the game anymore — I can’t even play it.