Your XABF sounds exactly like mine.
He will take you down a path that is hard to walk back up (financially) if he stays.
Guilt is a self imposed feeling. If he had borrowed money from GMAC to buy that truck and did not pay them, wouldn't that also repo the truck? In NY if you drive with no insurance they impound your vehicle and revoke your license!
You have done nothing wrong. Look 4ward, not back. Live in the hour if living in the day is too much.
Get to an alanon or Naranon meeting. Write here. Weaken and catch him as he falls and you hurt him far more than if you let him fall on his own and hit bottom.
... and dump the guilt. You have your self and your baby to think of. don't let him rent space in your head by feeling guilt!