Can I, as a seller, get out of the sale of my house?

I'll say first and foremost that you must review your contract to accurately know what rights and remedies are available to you.  You can try to terminate the agreement.  You can try to identify a buyer default that gives you the right to terminate.  You can ask the buyer to terminate the contract voluntairly.  You'd probably have to reimburse them their costs.  If you have a realtor, you may owe them their fee due on the sale b/c they did what they were required -- produced a ready and willing buyer.  I'd sugges that you have an attorney review the contract and details of the situation before you do anything.