urgent,please help

I signed a contract (sale by owner) to sell my house. Becase buyer is breach of contract, My attorney inform his lawyer to declare the contract is void. But buyer's attorney never response.
Under this situation, is the contract totaly void?
I plan to sell the house again. I want to know if there is any possiblility that buyer can do any legal action against me to stop me selling the house?

Thank you in advance.