Apparently it works best to be a wee bit of a thorn in their side - keep the caseworkers aware that you are waiting for a child and touch base regularly. And it's definitely easier if you are willing to take legal risk placements (although it can be heartbreaking of course too but you have to somehow be able to accept the possibility of reunification and find it in yourself to smooth the transition if the child goes back to the bio family). Do check out the foster boards onhttp://forums.adoption.com.
btw I know that the clinic here close to Fort Worth does donor embryo cycles with almost no waiting and as I recall for about $4000. Maybe that is something to consider?
So sorry this last cycle was a bust but "there's got to be a morning after" and I have confidence you will find it.