Randomely started lagging a few days ago

Basically, I have a bridge connection going from my laptop to my main computer, but this never caused any lag. League always runs smoothly for me with 40 ping and about 120 FPS regularly. A few days ago I decided to download League replay and look back on my games, but it didn't work properly and I uninstalled it. Then I tried OBS, and it seemed to be the cause of the lag, but after uninstalling that also the lag continued. For the first few games it was at a usual 120-160 ping. Then it stopped for a few games and stayed at 40 ping. It then bumped up to 200-350 ping, and currently it's usually anywhere from 120(rarely) to 600 ping. I've tried everything. Dropping my settings from high to normal, then low. Turning off all background tasks, capping my FPS at 60, then 30. uninstalling recent downloads(which shouldn't be a problem since my computer is only about 5 months old and pretty fast.) Flushing my DNS and even scanning with malwarbytes for possible viruses.

The lag is only in League. I can play games like Osu, Warframe and Game Dev Tycoon. I can also watch movies, shows and videos. Is there anything else that might be causing the lag? Or anyway that I can stop it from lagging?