In the Berkshires, the "forms" are different than those used elsewhere. It sounds like you ended up "out of contract" because you didn't meet the deadlines stipulated in your Purchase and Sale Agreement. These dates and deadlines are legally binding. If you are out of contract, the seller can keep your deposits as liquidated damages, and is free to accept another offer from another party - very attractive if they have another buyer waiting in the wings willing to pay more than you were. Did you use a local real estate professional as YOUR buyer agent , protecting your interests? Do you have a local real estate attorney? Dagmar's and Wendy's responses are right on. Use the professionals and their expertise.
The property itself may not be lost to you, but before you apply for financing elsewhere, you will need to be under contract with a fully executable purchase and sale agreement. It may mean renegotiating with this seller and drawing up new documents. They are under no obligation to honor the terms upon which you previously agreed. Make sure you are fully aware of all deadlines. When in doubt, clarify. If you don't, as you have found out, the results can be a very expensive legal lesson and a big disappointment.