You have a lot on your plate! You've found a good place to get some help and to understand that there are many others who have lived your story too and you are not alone. There is a lot of good information in the stickies (at the top of the page in this forum). Take some time to relax and read those, and several threads.
You don't have to do or decide anything right this minute (unless you don't feel safe, and you sound more frustrated than unsafe). You can slow down and think about some smaller steps you can take.
I would place your health at the top of the list. Please try to eat something and rest when you can. I know at 3 months I was exhausted all the time! Perhaps speak to your doctor about your situation. Maybe he/she may have suggestions to help with your nutriution when you are too stressed to eat much.
Once you decide to make yourself (and your child) your focus, instead of your ABF, it is surprising how options suddenly appear, in little ways and in big ways. This isn't selfish, it's good sense. You can't "fix" ABF or his situation, but you can work on you and your situation.
Sending warm thoughts your way.