Help Me Adopt My Stepson

So my stepson is 6 years old. I have been taking care of him since he was 2 1/2 years old. His mother is a drug addict/user. She has been in and out of jail and prison. The father and I tried to get full custody last year, since Colorado is a "mother" state we were only able to get decision making rights. I am currently trying to adopt him so that Jaxon can have a safe and secure life. He has never onced asked about her or really seen her, her choice at the time. He has been calling me mom, all on his own, for about 2 years now. I had to get a lawyer to fight this battle and it has gotten too expensive. Please help, anything will help. I really do not want to lose this battle. Thank you and God bless!