The Great Housing Market...

So I own a house. It's soon to be owned a house. My house is in Texas and when I pcsed last year I rented it to some friends for the price of the mortgage. I thought it was a good deal. They watch the house, I don't pay my mortgage. Seems like a nice deal. Well, they stopped paying, moved out and now because my mortgage company didn't have my address in time to inform me of the missed payments I am 13,000 dollars behind in payment. I have until May 5th to sell my home for at least 80% of my mortgage value which is currently about 112,000 dollars or it will be foreclosed. The worst part is, this isn't a bad house. I wasn't trying to foreclose and could have paid the mortgage if I hadn't been so gullible. This pisses me off and I'm upset that at so young an age I've failed one of the first tests of financial responsibility. Gargh.