9 year old with an additude

My 9year old daughter has a very bad add. with me for some reason, i don't know how to deal with it. It all started when DCFS came in back in 2004 and i had no control over it my x abused his son. any ways she has had this add. with me since then an it has only gotten worse with time i don't know what i am doin wrong. I don't spank my kids an when i do it don't bother them they just laugh at me and run away to go play again. I was with this one guy for almost six years and she had an add. with him too but it wasn't as bad, i have let her go see her father,( i have 3 kids two different fathers). well i let her see him and she came back early she was suppose to stay the summer but didn't. I am now seeing this new guy and she is very mean to me and him she calls me names and hits me and she treats him somewhat ok at times, but other times she is slamming his doors and calling me names follows me every where and tells me that i don't take care of them.
All of this really hurts me and i don't know what to do with her, The man that i am seeing he lets my kids run in his house and do what ever they want and he doesn't yell at them. She is so mean towards me and i am at the point where i don't know what to do i really need help with all of this. She has also written me letters that she hates me, I have tried to sit down with her and talk to her but it don't work i have tried to spend some alone time with her but after a while she starts up again i am really trying but nothing is working i am hurting bad here to know that my child hates me so much and i don't know what i did wrong some one please help me. Crying or Very sad Crying or Very sad Sad