Worried and need advice

[lilysdad]

I live in Tulsa, Oklahoma. I am the unmarried father of a 3 year old girl. My girlfriend and I have lived together almost five years. We currently live in one of the nicer areas of the city, I have a good stable job, and our daughter has been raised in a loving environment. Lately a serious problem has arisen. My girlfriend claims that she wants to get her own place, thus breaking up the family. I am 30 and she is 22, and she has given me some sob story about finding herself, missing out, etc.etc. In actuality though, she has been hanging out with another guy (with obviously questionable morals). She will not deny that a relationship with the individual is occuring because she is a bad liar. Anyway, my daughter is the light of my life. My girlfriend and I have drafted and signed a document we created laying out the days of visitation we have agreed on. Sun-Tues for me Weds-Sat for her. I have wanted to avoid court if I could trust her. However the last two out of three nights she has stayed out with this guy until 5:00 a.m at parties or at his house. Our daughter has stayed at home with me. This is irresponsible. My girlfriend (or ex, I guess) is supposed to stay until Feb. when our lease runs out, and I feel this is unlikely. Given the situation and my love for my daughter I want to get primary custody. We can have equal visitation because I understand that is important, but as for decision making I am far more stable and responsible. My ex has proven to be very emotionally immature. Honestly, I could care less about a reconciliation with the mother (though I wish our daughter wasn't facing a broken home). I am thinking of my daughter first, while her mother is thinking of herself. I plan to see a lawyer asap, but are my chances of getting primary custody in the situation decent? I need help.