Hi Keegan. I am very sorry to hear about this. How frustrating!
If your agent hasn't done so, I would have them inform their designated broker immediately. Assuming everything has properly played out like it should throughout the transaction and AAR contracts have been in place, the DB might be able to talk to the selling agent's DB and inform them of the situation so that it's hopefully rectified. A lot of time when legal action is threatened and you have a winning case, people shape up. Assuming you have an agent, your agent's brokerage might also have legal council on staff/on retainer and can be called upon potentially as well.
If you were unrepresented, I would contact the seller's DB ASAP.
You should also be able to get your earnest deposit back as well.
What reason did the Selling Agent give for backing out? You as the buyer hold all the backing out power that late in the game, so I am curious what happened.