Real estate purchase agreement question.

Hello, My wife and I have signed a purchase agreement for a property. The owners would not accept a sale contingency on our home. We've acquired a bridging mortgage. We accepted these terms because our sales agent told us on more than one occasion prior to listing that "we'd better be prepared to move because our place will go fast". Well, we listed Apr.1 and are due to close on the other home May 4. As luck would have it, we've had no offers yet on our place and are facing dual mortgage payments. Feeling is we were mislead to believe we'd have a buyer under contract prior to May 4 closing. We've provided 20k in deposit, closing will be another 46k. My feeling is we should walk away and take the 20k loss before closing rather than take ownership and gamble that we can resell that quickly. This is all in a desirable areas of south eastern PA. we've heard we may be obligated to wait 90 days before we are permitted to resell. Please advise on our options and best approach ? Thanks