My oldest daughter and my now ex daughter-in-law. My daughter had a baby and it fixed itself. My daughter in law had a miscarriage and I'm not sure how she is going with it. They both went through absolute hell, on a monthly basis.
I don't think having babies is that much more painful, tbh, and I had 7, without hospitals and interventions. At least with having babies you have an end-game with a reward. Endo just sounds like the most awful thing. Normal period pain, before my babies (because despite the fact that giving birth is crazy painful, it stops the monthly horror that is painful periods) was bad enough. I, kind of like giving birth, because it helped with my horrible autistic hormone issues. Having a severe lack of normal levels of oxytocin meant I was lonely beyond cope-ability, as a young person, and unable to feel connection with anyone, really.
Having babies helped. It gives a massive oxytocin increase, as does breastfeeding. I think, I may've been a bit hypo (lacking in) sensitive to pain, but still, I am in deep empathy for what you are going through with endo. I watched my daughter suffer so horrendously, I wouldn't wish it on my worst enemy (if I had one).