When I read your posts I come away with the impression that you have thought this through rationally. For what it's worth, I don't believe it's a selfish decision to prioritise the needs of your family as it is now. I recognise that you want to know how you're going to feel afterwards....but that's not going to happen. I will share my story as you asked for experiences of the aftermath of emotional decisions and I can centre this on terminations.
My first termination happened when I was 17 and was a no-brainer, as I was not equipped in any way to have a child. Nevertheless, I felt a range of emotions over the ensuing years. Did it add to my depression and anxiety or was I already on that path? I don't know. I made peace with it a long time ago and can think now about how old my child would be, what he or she would have been doing, etc without too much pain, although I don't like to linger on it. My second termination happened when I was 25 and I still feel ashamed of it, because it happened due to carelessness with contraception. I felt like one mistake was maybe ok, but two was not forgivable. So I don't think about that one very much, and again, perhaps those buried feelings are manifesting in my ongoing mental health struggles. Five years ago I had a child and she is healthy and loving, and I am able to love her. I wasn't haunted too much by memories of terminations during my pregnancy. I am able to empathise with and support friends and colleagues who seek terminations because of my experience, and that is something I value.
I would summarise my experience like this: it's a pain that is always there if I seek it, but it doesn't impact me every day. I don't think about it when I am with my child or around other people's babies, or talking about childbirth, pregnancy, or contraception. I wish it hadn't happened, but I don't regret the decision I made both times.
Finally, I would say please don't discount your need for mental stability for your own sake and your family's sake. You can't sacrifice your mental health for others, because then you simply won't be there for others anyway.
I hope that someone with more similar circumstances to yours is able to give you some insights, and wish you all the best.