S.B.
Sweetie, you aren't the reason he drinks. HE is the reason he drinks. He is an alcoholic, plan and simple. Our family lost a beloved niece, daughter, sister and mother due to alcohol 2 years ago. I wished we could have done more but you can't help someone who doesn't want help or doesn't think they need help. Her death has devastated multiple families.
You cannot force someone to stop drinking. You cannot make a deal with someone to stop drinking. You cannot beg a person to stop drinking. The only person who can make a person stop drinking is THAT PERSON. He doesn't want to stop drinking so he blames everyone and everything. His family WILL NOT HELP YOU. You have asked and they have answered. Now its time to protect you and your son.
Get to an Attorney ASAP. Take all evidence you have to your attorney. Right now, your husband has as much right to your son as you do. That needs to change. Join Al-anon. That will help you learn to deal with an alcoholic. Your priority is you and your son. Reach out to your family. If they can't or won't help, reach out to a women's shelter, or your attorney can give you information. You can get help. A drunk living in his car isn't going to get custody of a newborn. Breath... one step at a time... we are here