My question involves child abuse or neglect in the State of: New York

This situation has become a big problem for me and I'm trying to figure out how to resolve it. Bit of a long story, but I will keep it as short as I can. My ex has residential custody of our two children who are now 19 and 13. I realize the 19 year old doesn't figure into the equation much anymore, but for the last two plus years we have had a lot of problems, mostly tied to my daughter (the 19 year old), but now also my son on occasion. When my ex drinks she is a nasty drunk. Difficult to deal with when sober, impossible when she's had a few glasses of wine which is pretty much every night. Has on several occasions threatened to commit suicide. Told my son when he was 11 "I'll probably be dead before you get up tomorrow morning". He was so upset he called his sister at work in tears. Told my daughter one night she will just sit in garage with the door closed and the car running. Argues constantly with my daughter and if she's annoyed at her will prepare dinner for my son and herself, but not daughter. Hates me for reasons I truly don't know and bashes me at every single opportunity. Tells them I don't pay her when the truth is I've never missed a single child support or maintenance payment (when I was still paying maintenance) to the tune of about $500K over 13 years.

She complains to everyone about my daughter who is a terrific girl. Works hard, goes to college and studies hard to be a radiologist, but her mother constantly complains she doesn't do enough around the house. Kids are kids and maybe she can do more, but her mother is never nice about what she says and how she says it, bashes her on Facebook and to patrons where she works to the point that the owner doesn't want her there any more. She took the insurance off my daughter's car while she was out driving it. Took the plates off it while they were on vacation with me, sent her pictures of the plates and said "the car is mine now. Figure out how to buy yourself a new one." Always harsh and nasty. She told my son "Your father beat your sister when she was young and left her with bruises, that's why she hates him". Nothing could be further from the truth. Notwithstanding my ex's efforts to drive me and the kids apart she has pushed us together. I have an amazing relationship with them. They trust me completely and don't trust their mother. My son is in Tae Kwon do and was going to his belt graduation ceremony and my ex texted not to come as they weren't going, saying he wasn't ready. The next day she texted me "By the way....we went to the graduation last night". She lied to make me miss it. The kids hear their mother on the phone complaining to people mostly about my daughter which is so demoralizing to both of them. My daughter and her mother argued over the coffee mug my daughter left in the sink telling her "You'll have to get your own cabinet for these, I don't have room". That's ridiculous because it's a big kitchen. My daughter said "Fine I'll move out and get my own place" and her mother responded "You can't because then I'll lose the child support". My daughter told me the story and said "Mom didn't say Don't go because I love you and I'll miss you, she doesn't want me to go because she won't get money. All I am is a pay check to her." It broke my heart.

This week my daughter and ex argued and they actually put their hands on each other. My daughter says it was in self defense because her mother came at her. No injuries, but my ex threw her out of the house. My daughter called me hysterical crying saying "Mom threw me out"! While the argument did got out of hand, but daughter tried to leave the room and her mother blocked her and finally grabbed her to make her sit down. If she had let her leave and allowed things to cool, none of this would have happened.

I'm barely scratching the surface and sorry if my story is a bit disjointed. I'm trying to convey that the atmosphere in that hose is constantly at a high stress level. The kids are afraid of which mother they will find when they get home.

Here's the problem: I live 50 miles away in my mother's house because I can't afford to pay child support and get my own place. I visit for dinner every week and every other weekend I get my son as my daughter works. I have made the trip over 2400 times over the last 13 years to spend time with them and take every opportunity, sometimes 2-3 time in the same week. I'm heavily in debt because we battled for 3 1/2 years over custody as she wanted sole custody and I would agree to nothing less than joint. I ended up over $100K in debt and could afford nothing. Meanwhile, when she cried to me that she didn't have money to pay the electric bill, I gave her $200 unsolicited to help out. The next day she left on vacation with the kids and came back with a brand new $30K car. I felt like a fool, but the kids knew I tried to help. I have their respect and that's all I care about.

The question: How do I file for custody of my son without spending $20K+ on legal and other expenses? Most of my evidence of her behavior concerns my daughter and to a much lesser extent my son. Those children are in a toxic environment and I need to get them out. Any advise is welcome!