I understand very well what you mean. Good that you found the one to show you the bright side of the life. I am also getting in and out of depression after being pregnant with my first baby and lost it in the beginning of the 3rd trimester. But when I start to feel very depressed I think to myslef that I have to move on because I really want to have a child and I won't give up on my dream.
Actually I gave birth but he was too small and lived for a month under special cares. He was a little 700 gram fighter - my baby angel. I believe that each and evey person has his time and mission on Earth - one may live 100 year and someone else like my baby has only a month time.