There is a lot of area between the status quo and "I'm leaving right now". I cannot say whether you should move out or not, but there are other ways to protect yourself, your sanity, your peace of mind, and your son. For example, if I remember correctly, your AH has had his license suspended. So, decide that you no longer will be a passenger in a car where the driver has no license. Period. Not your AH, but any driver. Then when he asks why you're not getting in the car, you can simply let him know that, and walk away.
For me, an important part of determining my boundaries was quantifying them, articulating them in words to myself, and deciding how I could effect change in my life and the lengths I would go to protect my boundaries. Don't make it about him, make it about you.
Regardless of what you decide, stick to it, especially if you say it to him. Good luck!