Pre-Approved For Mortgage Is Lost Due To Equifax Credit Score Blunder

All was well when I was pre-approved for a mortgage in September, that’s how I put in an offer on a lovely house, and the seller accepted. Apparently, since the pre-approval, my credit report by equifax shown changes, no idea why….now I'm more than $250k overdue! The worst part is that I don't even own it. I went to the bank, and they told me it was all an Equifax mistake. It can’t be… nothing has changed in my finances but they keep me low profile like this, I won’t accept this…when I contacted them they said there may be a mistake in the records and they’ll need some time to fix things through, the catch is that I have an impending due date. I risk losing the house if it isn't resolved by then. Without exception. What comes next? Feeling completely overwhelmed.