Hello. It’s a big question, isn’t it?
I can understand your concerns and doubts.
If you are young enough then maybe you have some time to work it through, too.
I have three kids and at times, yup, I wish I had more alone time, and at times, it just feels like a lot of hard work. It’s cliche I know but the magical bits of it make it worth the tough stuff, for me. I know I’ve grown a lot as an adult by having to make these sacrifices - but then I don’t think any less of adults who don’t have kids. It’s just that there was something that clicked in me when I first looked after baby #1… a few weeks in, I looked at my own parents with completely new eyes. I actually realised what they had done for me. At 34 years of age, until I’d had my own, I hadn’t really appreciated them. So, there’s that!
In terms of being 100% sure or your partner before committing to children with them, well, no one can ever be truly sure. Things may change. In my case we are still together and it feels stronger than ever. But I also want to leave room for my partner to grow and for me to grow - ideally we grow together - but there’s got to be enough space somehow for all 5 human beings in our house to occupy and work out who we are becoming.
Letting go of control is something you learn through parenting. It’s a worthwhile lesson!
Best of luck working it through