I'm sorry Sometimes healthy mourning is necessary to bring you through a difficult time in your life. I agree that it is good to be appreciative if what you have, but I also think that it's perfectly reasonable to mourn what basically is the loss of your fertility.

If expanding your family is something that you truly have a desire to do, don't forget that there are other options for doing so. My own family (and my sister's family) grew through international and foster-care adoption, and I have been helped two families grow by acting as their surrogate. Families come together in all sorts of ways