Frustration?

I seems like it never fails - Anytime I go to my "doctor"; I always end up in a room next to the room where a woman is hearing the heartbeat of her unborn child. I've started to think of it as almost torture! I've not been able to get pregnant in the past 6 yrs and even before that I'd tried. Problem is I lack the Progestin or Progesterone (whichever it is) -- I have way too much Estrogen and that's what causes all my issues and also prevents me from becoming pregnant.
At times, I go through the motions of wanting a baby and then not wanting a baby this far along in life. In any case; I'm always disappointed that I wasn't blessed with children. I've pretty much hung up the idea at this point. J is almost 40 and I'm going to be 32. I just get so depressed sometimes because if anyone ever wanted to be a mom; it was me! I often thought about what he/she would look like and what pregnancy would be like. I've always felt like I was meant to be a mom but at the same time I kind of had a feeling that it would never happen. Almost an intuition. Now, I sit back and look and I realize that pretty much every one of my friends has children. I sometimes feel like I have nothing in common with them anymore. I know that is so far from the truth - but I can't shake the thought. Birthday parties for their kids can be such a drag because I sometimes feel like an outcast. They don't make me feel that way at all but it's just how it is. I often wonder if people just think I never had a desire to have children. Most of my closest friends know that I've always wanted children. Ugh!! It's just so hard sometimes.