Hey... So this is a throwaway. I can come back and answer to things but I just want actual advice that isn't from my family around! I will try to include as much context as I can. If I sound like a complete shithead please tell me that I feel like a shit head...

I (18 nb) am going to college next year. It is something I have been told by my parents that I have to pay for myself the whole way through, something that I have made peace with and am working on right now getting more scholarships and a better job to help with that.

My mom (45 F) got pregnant by my stepdad(53 M). She's happy, I'm happy that she's happy. The issue is that it is starting to dawn on me that she wants me to take care of it. There isn't exactly anyone else around the house, my step dad who is the father of the baby is back in another country doing work things, the baby happened when she went to go visit him for a while.

She got upset when I told her my college isn't directly nearby the house, asking me how I was going to 'help out' if I'm constantly driving. I never told her I was planning to move on campus for college, if I did tell her it would be a whole thing involving crying, screaming, giving me the silent treatment, so I was just going to pack my shit in my car and drive off. I never planned on staying in the house or having any sort of connection to the baby, because when I did I know it will be used against me. We both know she can't take care of this thing by herself, but I am also a stupid barely adult who needs to get a degree and pay for it.

I think I am going to list off bullet points of context to keep this a somewhat reasonable size.

• she works night shift
• any family that could have possibly helped her in taking care of this baby wants nothing to do with her, it's been this way since I was three. i am fine with my extended family and frequently visit, she is not. It's an ongoing joke that I still 'put up with her'.
• my step dad will be at the birth, but has to go back eventually and fulfill what he is originally doing for work.
• I have been backing and forthing with her about the baby's vaccination. She doesn't want it vaxxed. Entire other debate, I know, Uncomfortable about that.
• I have autism with a specific dislike for loud noises, in the past when I tried to do babysitting I actually had to be taken home by my dad (46 M) because I was having breakdowns due to baby crying. I don't want to be that way, but unfortunately I am.
• I must emphasize that I am a stupid barely adult.

She leans on me even now, with house work and money and whatever she needs. I didn't have a problem with it before until now, but this is more than doing the dishes or cooking dinner. It's a whole human being, and due to past experiences, if I give her an inch she will run a mile. I don't really know what I should do, if I should stay and take care of it, should I just silently leave forever. I am absent father-ing and I didn't even make this thing! Crazy. At the same time I feel bad for the potential kid and her for having to go through it alone. There is literally no one else but me, and she really wanted another baby.

What the hell do I do with this? Is my og plan to move away selfish? Am I making the right decision for me??? I feel like this sort of thing is wayyyyy too much for someone like me rn. AITAH?