need push in right direction

This isn't really related to depression, but because I am a sufferer, I need advise and nowhere else to turn.
As some of you know, I was in an abusive relationship and have a son from it. The "sperm donor" has not known where we are since we left years ago, have had no contact, child support, nothing. My son is seven now and I am not looking forward to the day he asks if he has a real father. Anyway, in preschool and in kindergarten, the schools were very cool about having the sperm donor's name on a list of people that can never pick my son up. My son's last name is hyphenated with my name and "his". Now that my son is in first grade, they say they can't legally respect my wishes and only use my last name. My son doesn't know this name exists and he corrects people when they "get it wrong".
When the time comes and he asks, I will of course, tell him the truth. In the meantime, I desperately want to legally change the last part of his last name. Today, my depression has turned in to anger enough to get me thinking and decide that I am not waitng any longer for my fiance to legally adopt "our" son. I looked on-line, and all I can find is info. on adopting, divorce, that kind of stuff. Nothing specific to my situation.
I am asking if any one here knows where I can go before this research gives me an anxiety attack.
Please, please, please and thank you, thank you, thank you! :)

Hi holly, Jwalter is right most states do offer free legal advice especially if you have a low income...I am not assuming that you do here just that most single mothers struggle.  I think it is called Legal Aid or something of that nature...sorry I'm not much help

Hi Holly, go to a website www.prepaidlegal.com. I used to pay $26/mo. for unlimited free legal advice. The advice comes from "real attorneys" at "real lawfirms." You can pay one month and use the service right away. I hope this helps. Good luck with your endeavor and bless you and your Son.
Kelly