I am not sure I fully understand the situation, it seems that there are no Realtors involved. Am I right?
As you are not talking about your Realtor and you are not talking about the Buyers' Realtor.
And I also do not hear anything about a real estate attorney/s.... Either one of them The Realtor who listed your home, your real estate attorney who would look over the contract, could clarify the situation for you!
Look at your contract, have a real estate attorney look it over if need be, and see what the clauses are
that will allow a buyer to get out of the contract.... (for example cannot get the loan would be one! Found something wrong during inspection would be another one)
You need to connect with a professional if you did not do the contract with a Realtor on your side and a real Estate Attorney.
Good Luck to you!
Edith Karoline YourRealtor4Life!
Working always in the very BEST interest of her clients...