Who has custody?

You need to post this on the Legal forum so an attorney may respond

I have my 9 year old son with me. I am in a great dilemma @ this point. Myself, his mother, and he are from NC. I now reside in GA. He has been in my physical custody for 9 months. His mother is in an active case with DFCS. First, I need to know who has “legal” custody at this point. He is with me because DFCS told me that they “think” the law in NC is automatically joint custody between unwed parents unless their is a court order stating otherwise in which we do not have. So currently DFCS has legal custody of her other son since his father would not step up; but grandmother has physical custody. My son is not in the case and there was no order from the judge. I want to sue for custody but no attorney in NC will talk to me over the phone. I have been told everything from I have no rights to my child, you may file in GA, you have to file in NC, you can file wherever the child has resided for the last 6 months. I cant afford an expensive attorney so I want to attempt this on my on. She has agreed to joint custody but she wants the child to reside with her. She is currently still on drugs and this case has been going on for 6 to 8 months. What in the world do I need to do???