There are several dna testing services that can be of great help in establishing family connections. This is particularly true for males. Family Tree DNA is a service that I used and I can vouch for the integrity of the service.

I recently corresponded with a guy from California that had been adopted by an American couple visiting Spain in the 60s. His birth mother was Spanish and his father was unknown. His wife had given him the test as a Christmas gift because he had expressed curiosity.

He was convinced that he would find that he was of European descent but it turned out he is 99% certain to be a cousin of mine. Apparently a U.S. serviceman had had an affair with his mother and probably never knew about him. He might find his father if he can find a military person with my family name that served in or visited Spain around the time of his birth.

If you are interested, the service will establish the male side of your family with great accuracy and it will establish your haplo group to determine your original roots. You may never find your father, assuming you even wished to, but you will know with a high degree of certainty what your genealogical surname is.