Weird internet lag

So this is a weird problem that i have and i havent been able to find the answer to anywhere else. Whenever i start up a game on steam(counter strike to be exact) and i goto the find servers button all of the servers show up pretty quickly and my average ping is around 50-90. Seems ok right? But whenever i actually join the game my ping rockets up to the thousands and i eventually have to leave the server. After i leave the server i will completely loose internet access and i wont get it back until i restart my PC. I have no idea whats causing this but id like to figure out the problem and fix it.

Thanks,
-Nick