It's always best to begin in the right place. Our recommendation is to present your delema, through your agent, to the buyers. I'm sure they will be disappointed but hopefully will be understanding and compassionate.
It may be beneficial to present them with a letter documenting your situation. You should be able to back out of the transaction in one of two ways....inexpensive or expensive. We're hoping your buyers can see their way to being understanding.
It's always a good policy to consult an attorney on matters that could involve legal action.
I am surprised at some of the posts I read. In your case. you have an attorney representing you, correct?
I would defer any answer to your attorney, who has knowledge of the documents and transaction, and most importantly, represents YOUR interest. You are paying them, right?
So, not to be unhelpful, please direct your inquiries and concerns to the professionals representing your interests.