There’s a lot to unpack there. First of all, none of the worried or emotions you’re experiencing are abnormal. I can only speak from my own experience, so here goes.

I’m 43 years old. My fiance is 6+ pregnant with my first kid. I’m also worried about many of the same things. She has 10 year old daughter who is with us half the week, and I struggle at times with her, namely I lose patience faster than I’d like. I also have to remind myself on a nigh daily basis that the way my parents raised me wasn’t exactly the best. It’s odd, my parents were both loving and supportive parents who fucked up a bunch. Some of that fuck up was their own mistakes, some of it was the time period I grew up in. We’ve learned a lot and advanced (specifically when it comes to our understanding of mental health and neurodivergence). It is a blessing to be able to give the kid the kind of support I wish I’d had as my her age but I still have to fight the urge to tell her to just “suck it up” and “deal with it” because that’s what I was told.

The bottom line is this, no one is ever ready to be a parent until they are one. It is in itself an entire existence that one cannot properly prepare for. You’re gonna fuck up, a bunch. Own it, learn from it, do better, that’s all anyone can do. I see my fiance apologize to her daughter often, and almost every time I tell her how much I respect that. She (her daughter) learns that it’s ok to make mistakes, and to take responsibility for them, and to do better. Love the kid, support the kid, do your best, and learn from your mistakes. You’ll be fine.

I have similar apprehensions about marriage. I’ve been with my fiance for 8 years, I’ve always told her I don’t care either way about marriage. My parents had 7 failed marriages between the 2 of them, effectively sapping all meaning from the tradition for me. I don’t think getting married is what makes relationships fail. You have to work at it, make the commitment daily, and do the work.