I don't know what's wrong with it, but I would really appreciate it if someone can help me. I've already been receiving money from this address so I really don't want to delete it. I have 3 BTC coming in.
You should backup and secure/encrypt your wallet before messing with anything. If you have a second computer, I'd recommend getting the software working there and ensure that your wallet works on that computer.
If you're running an older version of Bitcoin-Qt, upgrade to 0.8.1 or later.
Check out this other question after that.