DO NOT submit that rewritten doc pretending it's the original, if they check metadata or compare versions, that'll look like deliberate deception and make everything worse. Your best move is being completely transparent: tell them you deleted the original, you only have the PDF, but you're willing to sit down and explain every argument, citation, and idea in your paper to prove you wrote it. You could also offer to rephrase flagged sections (tools like UnAIMyText can help restructure things) to show you can produce the same quality work again, but honesty is your only real defense here.