There is WAY TOO MUCH we do not know about this transaction or your situation.
As you know, the devil is in the details of the contract you signed. For the owner, God is in the details of the contract you signed. (You may have contractually agreed to a purchase price) We, reading your question, do not know what you signed.
I would suspect you feel into a trap. Not really a trap. The details ARE in the contract you read. Those trying to circumvent the PROTECTIONS in place for home buyers often find themselves in a situation similar to yours. Consider working with a pro in the lending and real estate professions to position yourself property before your next real estate purchase. These processes are in place for your PROTECTION.
Best of success to you,
Annette Lawrence, Broker/Associate
Remax Realtec Group
Palm Harbor, FL