I am currently in china, and have had no problems with my blackberry until this weekend which is 2 weeks into my trip. My OS is not working and it keeps restarting and when it does work it takes forever to do anything...what could this be?

They are some issue while the radio on the Berry will cause a shut down, Verizon Berries had this issue in Puerto Rico, device detects that is roaming and tries to attach to the new roaming network and then shuts down, lucky for us VZ released a new OS that fixed this radio issue. I would suggest to update to the latest OS available from your carrier or try the BETA 4.5 that is floating around the internet.

Omar