You are not making the decision to become a single parent. HE is.
Children would rather come from a broken home than live in one.
How two consenting adults choose to live is their business.
But for God's sake, the kids do not deserve to live in turmoil and the everyday hell that happens when a parent is addicted.
Good luck with nursing school, it is tough. Lots of studying and focus needed. I can only suggest you educate yourself about addiction, I have a feeling things will get worse, alcoholism is a progressive disease.
The disease is already showing itself, no job, no money, soon no car,...... these are all his consequences, coming to the surface. I would step back and let him experience every damn one.
LaLa, you cannot save him, so save you and your child.