Family Lawyer Retainment

Would like to raise enough money so I can retain myself a family lawyer.  In 2015 I went through a divorce, and the only way that she would agreed to go through with it if I accept child support for one of her girls.  She is NOT my biologoical daughter but raised her since she was 2 and 1/2 years old.  Now she is 18 years old, she turned 18 last December, and payments are still in effect until I go back to court to stop them.  Her mother is bitter against me and has turned her against me, she doesn't let her daughter communicate with me, I haven't even spoken to her in couple of years now, so I don't even know what's going on. Anyways, my current partner and I have a son Malaki, he was born December, 2015, and is almost 2 years old now.  I want to retain lawyer to put a stop to this order so I can have more money and support for my biological son, whom is my life. Hoping to retain a lawyer asap. Would be so grateful to put a stop to this and move on with my son and partner.  I hear that my step daugher is no longer in school and is on social assistance, living with her mother, I don't think it's fair that they are deceiving Maintenance Enforcement and myself, my payments should be stopped. My ex wife does have her degree in Social Work,  she makes more money than me.