Getting my daughter. Any advice?

So I was with this girl for 8 years, she became pregnant. I was ecstatic, she wasn't so. She wanted to binge (drug/alcohol) and I gave her an ultimatum. I said it was me or that, figured she would shape up, but instead she shipped out to some other guy who was supplying her with that crap. I kept trying to contact her during the pregnancy but her family acted like rabid watchdogs. They eventually said she had an abortion and to leave her alone. I was devastated at hearing I lost my child so she could party and all that crap. On Friday, she called me up and said I have a 4 year old daughter (her name is Ciera Love, born on valentines day, and quite the cutie by the way). She also said that she entrusted care to her aunt, who is a known junkie, just not on criminal records. Her aunt got the girl to sign away maternal rights with threats of a long drawn out court process. She said that her aunt is going for sole guardianship and is trying to claim negligence on my part in order to supercede the necessity for needing me to sign away paternal rights as well as child support. Her aunt told her that she better not tell me or else....(buh buh buhhhh). Anyways, she filed petition for sole guardianship on Friday and this morning I am going to the courthouse to contest it. Her aunt also has the habit of taking kids in her family that might get taken out of the home and going on the run and into hiding. She has done this when DHS (Department of Human Services) has gone to take kids out of the home and even on the suspicion it would happen. My daughter lives in a heroin/meth den. It is my duty and obligation to get her out of that hell. Do I stand a chance? Any advice would help greatly.