Can anyone help me feel better?

Well like a I said before, I raised my stepson for a period of 7yrs and his mom was never involve in his life. I took good care of him really good I did what his real mother didn't do for him.. Now I feel so sad and I don't know what to do because, I went to picked him up from school and they said he wasn't there anymore that his real mother checked him out from school, and took him with her. She does not want to bring him back, and she enrolled him in another school.. I already ask for help and there's nothing I can do.. They say she has all the rigths for being the biological mother. I don't think she did the right thing she did not want him when he was a child and now that he is a big boy he is 12 already, now she wants him.. Also she is trying to buy him, she says that she is going to buy him anything he wants I don't think that is fear can anyone help me feel better...