Everytime I join a match I get kicked after around a minute of playing. It says "lost connection with opponent" and then I logs me out of the entire game and I have to log back in and everything.
Any ideas why this is happening and what I can do to fix it?

Generally this means that you have a poor connection but it can also be due to that server is down.
I think that you connection is slow thats why you are always kicked out of he game.
What is your connection?
Try to take a speed and ping test.

I just did a test and it says 85ms for ping and 11.39 for speed. Is that good or bad?
I play other online games on this computer and have never had trouble staying connected.

85ms is a touch high but not terrible, your bandwidth wouldn't be a problem. I sometimes get kicked out of servers with a 'lost connection' message if I forget to turn off my P2P before starting the game. Are you sure nothing else is using your connection?

Which location did you used to test ping. If its near you then you will get lower ping.
Ping means time taken to send and receive data.
If your ping is 85ms. It means it will take 85ms to send and receive data.
Try to check farther connection.
Well your speed is hell a lot better than mine.
I get speed of 0.54mb and ping is usually between 320-480. But i have never encountered any problems.
Also stop any downloads or updates in background.

I have nothing up other than crysis 2... I seriously dont get why this happens in this game and not a single other game I have ever played. This problem did not happen on the 360 version. and I'm not sure how to turn off p2p or what it is...