I would actually approach the seller (via telephone or email--not in person. People get emotional about property). If the seller is reasonable and honest (good luck), you should be able to come up with something. If the seller balks, threaten a lawsuit. Even if you cannot afford to sue, don't let the seller know.
If you used real estate agent to buy the home, go to the agent and explain things. Basically, you're not asking the agent to solve your problem (it's highly unlikely he/she cannot), you want a referral to an attorney who will give you 5 mins to explain the situation. The agent (or the agent's broker in charge) should know at least one attorney who can give you a free consultation to help you better assess your options.
If you didn't use an agent to buy your home, simply consult the telephone director for an attorney. Ads for attorneys will be quite easy to find, for they are probably the biggest ads in your directory. Call around until you find someone willing to give you options.
Real estate broker (not licensed in PA)