I need advice

I have always wanted children but I have PCOS and Endometriosis so it’s very frustrating to be always excited about being a mom one day and having this situation which I know I’m not alone. My sister who wanted to have like 1 kid in her 30s ended up pregnant at 18 and Just had her 2nd daughter on 8/24. she brought the baby home and is asking me to help because I’ve always been great with children and if I had no issues and found myself pregnant tomorrow I’d fall into the motherhood roll pretty easy. Anyway, but it’s just really hard to sit here and watch/listen to her complaining about little motherhood things or how cute/perfect her child is and feel like why are you complaining when you should be like I’m lucky I have 2 beautiful daughters and no issues conceiving and your doing it at a good age... I recently turned 29 years old, I wanted to be maybe like having my 2nd or 3rd child by now. Also, my best friend is pregnant with her 3 child, her and my sister bonded more and I feel like some outsider anymore because I don’t know what nipple cream is the best or whatever but point of the story is, how could you distract yourself from those “your broken” thoughts? Those thoughts where you just feel defeated, half of a women feeling? Not saying you have to have a baby to feel full women but for me it’s something I’ve always wanted to have and I feel like it’s not going to happen. I try to push each day and keep positive but it’s getting harder and harder, and I also have no one in my area that has the conditions I have so I feel so alone and no real support team. I’m not wanting my family to not enjoy their lives or walk on eggshells when around me but I just wish I could experience the thing I want so bad.