Lauren
Try the voters register, is he named on your birth certificate?
Might give you an age etc
I've traced many many people with little information with amazing success (part of my job). Obviously makes it easier if he has an unusual name.
Do you know what town/city he was from?
Might mean you have to make a few calls to random people in the phonebook, from experience I've found most are very willing to help.
If you think you know where he is from you could put a small ad in the local paper asking if anyone knows of him could they ask him to call.
I wish you the best of luck, if I can be of any help at all I will.