Aw op, I really think this is one of those things that no one else can answer for you.
But my two sense, for whatever it is worth:
I always told myself I didn't want kids- and on reflection, that is always because I thought I had fertility issues. When DH and I started trying, I kept saying to everyone "it doesn't really matter anyway, I am probably infertile, so we'll let fate decide, etc".
Lo and behold I got pregnant almost immediately. I did not connect with the baby in utero at all. I had a horrible pregnancy and spent 35 weeks worrying that I had ruined my life- all the things you say kept churning around and around in my head, and at times I seriously wondered if I should have chosen to stay childless.
Anyway, along came DS, and I am so so so glad we have him! As sanscollier says, it's very much impossible to describe how suddenly you understand what it means to love something more than you love yourself. And I am not in any way being disrespectful to anyone who doesn't have children, it's just one of those things that you can only experience if you do decide to have kids.
All that said, I know that if we didn't have a child, I wouldn't know any of this, and wouldn't therefore feel that I was missing out. I also never had that nagging feeling of wanting a baby. Had we had to go through IVF, we probably would never have DS as we wouldn't have bothered...
It's hard, yes. It's tiring, yes. But we aren't skint, our marriage is probably stronger now than it was before, and we still see our friends and have our own lives. We also share lie ins so get one a week!
So- for me the positives far outweigh the negatives, BUT we will b stopping at one so that continues!!!