This is where you have to get creative. If you still can't tell where to go from there, try some books that are out. Check your local library for these and other titles of books that can help. They can sometimes suggest things that you wouldn't think of yourself, and really help keep up your spirits when things move a bit too slowly. ALMA has one of its own, but claims it doesn't maintain it unless you pay your annual dues.
Most states also have one as well.
Contact your state bureau of adoptions for information. You can also try placing an ad in the personals section of major newspapers in the city where you were born every year on your birthday. Birthparents will certainly be thinking of you on that date. They do no good if no one ever reads them. Finally, try not to become discouraged.