weird lag, won't let me re-enter game

I started a game normally, but when it started, there was this weird lag, like as if my MS and FPS were dropping, while on the top right corner said my fps and ms was normal. So I disconnected, to re-enter later to see if the problem stopped. After waiting a long time for the client to load, i clicked reconnect, to which it said "game in progress". Then, after a long time(while I was writing this actually), the game started to which not only was I massively behind and so was my adc (I was the support), the problem still persisted, and I got the afk warning when i re-entered. So I DCED again and continued writing this. I hope the problem doesn't appear again, and that I don't get punished for this bug.