Well, I was going to suggest the foster care system, but you said you have tried that. My husband and I were relicensed less than three years ago (we've done foster care off and on all our marriage), and are already probably on our third adoption, and we really only intended to adopt the older brother and sister of our little boy (didn't even know the little boy was conceived. In the end, mom got the older ones back, but reliquished her baby) Then our next foster child went home, and we got two little girls within two weeks of her leaving (they were not sisters). We adopted the older one, and the second one went to a relative placememt, and six days after she left, and three weeks after the adoption of our daughter was final, we were asked to take our daughters full sibling five month old baby brother, and he will almost certainly be an adoption, too. That will give us 10 children, seven biological, three adoptions, but how could we turn her brother down?
I think if you hang in there with foster care, you will end up with a child. Our first adoption, our son, was actually our daughters foster son, and we got to help care for him from birth. Our second, our daughter, came to us when she was two and a half, and her adoption was final December 20, she was four. Her little brother, who came to live with us nine days ago, just turned six months.