I'm really panicing right now.
I had over 2000$ in my offline wallet (Multibit) on my PC and it won't turn on. What should I do??
I realize that you don't want to hear this, and that it doesn't help you right now, but for anyone else that might be reading this thread I just wanted to point out that this is why you should create a backup of your wallet and store it in a secure place.
I assume you are not using MultiBit-HD? If you are, then you should have been presented with a list of recovery words (probably called "wallet words" by MultiBit-HD) when you created the wallet, and you can completely recover your wallet with that list of words.