How screwed am I?

Forging? Doctoring? Just Sign it? What are you guys.....? These are all CRIMES and you have now made yourself an accessory. Yes you can have state requirements but federal law trumps state(s) law. There are legal and legit ways to solve your problem. Find out what they are in your particular state from someone who actually knows the correct answer. I get some of your answers. It's worked for you before. Doesn't make it right.

The best piece of advise you got so far was, do not put a dime into the vehicle until you get this sorted. If the vehicle is confiscated. They take everything.