Please don't kill me anyone, but I am so troubled by this horrid situation that I have to speak. I can be harsh at times, but it all comes from experience.
Yes, DH is being a jerk. Sounds like he needs to grow a backbone. But YOU need to grow one, too! This no longer about him, it's about you and a child. You are faced with a challenge, step up and meet it.
You and how you act are currently being driven by some very strong hormones.
Decisions should be put off because of that. It is affecting your personality and you may not be aware of how. Time to grow up and have faith in yourself, though.
You do need to become more confident and independent. Get Mom to start teaching you to drive, and practice it. Start asking now about how you can get help- contact an attorney about the separation and divorce issues, contact a local job skills training office about learning, find a job.
Document everything, and don't take his word for anything. Trust me on that one- once the papers are signed it's probably bye-bye. And you won't get a cent after he disappears on you.
You've got 6 months to think about adoption. Use that time well, and stop whining, start doing. Many kids raised by single parents are doing quite well. You are no longer a kid, life has just up and whacked you as an adult.
Don't count on any money or help from him. Show him that he's not really needed. Cowgirl up- do it on your own. Don't be so reliant on the online world-we can be there for support and advice, but YOU are the one who has to do the work.
Harsh, but real. Many, many hugs to you.