My camera and sound is messed up what do it do?

I dropped my s3 into a stream for maybe 30 seconds, i took it out and immediately went to radio shack the guy said to let it dry out naturally because i couldn't press buttons. It fixed and everything worked except for my camera it is black and keeps saying it failed to load. Every app that uses the camera doesn't let you use it , and my sound is messed up and sounds weird. What do i do?