This is a tricky one for sure. But I don't think your life has to stop. You can find a supportive, understanding partner; it just might take time. I don't think chronic illness is something you necessarily have to reveal on the first date, but if things are going well, I wouldn't wait too long to share it. You can have conversations before you have sex (not just right before it's happening, but days before) about your needs, boundaries, and how the two of you can work together to make sex enjoyable. Reading the articles here can be a good start to know how to talk about it: https://endometriosis.net/sex-intimacy.
You can pre-medicate with pain medication before sex and also take it after. Heating pads may also work. Look into the idea of aftercare (it's often spoken about in the kink community, but it's a helpful idea for any couple). What would you need to feel safe and comfortable after sex? Think about what you would need and ask for it. If the person you're dating isn't willing to do the things you're asking for, you may want to consider if they are a good match.
I can't speak to having children because I didn't want kids, but I know many people in our community can give you ideas about how to navigate that.
I wish you so much luck and I'm sending you big hugs. Please feel free to reach out to us any time. ~Katrina, Endometriosis.net Advocate