My Ex Husband Is Trying To Take Full Custody

So my ex husband and I had agreed it would be a good idea for me to travel nurse to help pay off debt. I would help him pay off some debt as well, send him money for the kids, and he didn’t need to pay child support while I was gone. We had discussed having an affidavit drawn up just stating certain things because I was afraid he might try to say I abandoned the children and left to travel. He agreed to that, until one day(I’ve already signed my contract at this point at my hospital) I was trying to discuss it with him and he completely ignored me. Tried multiple times to discuss it and text him. Everytime he ignored me. Said he would never do that to me and we’ve already talked about it. He would never take the mother away from the kids. What a POS liar!!! We are 3 months into me traveling and he sends me a civil summons to take full custody of the kids, wants child support, to claim them on his taxes… like I am baffled. He texted me a week before I received this papers asking if he could claim the two girls even though in our divorce papers it says it’s my year. I told him no. He can claim our son like it states in the papers. So I think this pissed him off. He thought I was going to be up here making loads and sending him thousands of dollars apparently. I have been doing my best paying for all of my bills back home and a new place where my contract is. I’ve sent him $735..that’s more than he would have sent me in 3 months(his child support is $130/mo. He says I have had minimal contact with the kids. Which is not true. I have screenshots of all the call logs and texts from my son. I’ve only seen the kids once since being on the contract. I have to get approved dates to come back home, I can’t just pick up and leave when I want. I’m here working and they make my schedule. I am doing this for our kids! So I can pay off the debt I acquired during our divorce. So I can provide better for my kids!! Now he is trying to take them from me!!!! I cannot think of a more evil thing for someone to do to someone. After he encouraged me and supported me doing this. I have text message proof of everything. How can he do this?!?! Does he even have a case? If I have proof of his support, proof of contact with the children, proof of me sending money and waiving his child support. Like what kind of case does he have here? In my opinion he just looks like a money greedy idiot who doesn’t keep his word and is putting our children through yet another custody battle. The only way I see a mother losing her kids is if it’s beneficial for the kids, or she is a bad mother. I am not a bad mother!!

I just need advice on what to do because I’m losing my mind just thinking of even the possibility of losing my joint custody and him taking full????????????

Just a little side note to show you how big of a POS he is…he filed it on my birthday. Also going through finding a knot in my breast that I’m scheduled to have a biopsy on. He’s just plain evil. If there is grammatical errors in this, I apologize, I am really upset!

Location is Alabama that we all live in. Pennsylvania is where my contract is. We currently have joint custody. The children normally would do a 2/2/3 spilt. So for example I have the MT, he has them WTh, I have them FSS. Then he has them MT…etc. since I’m on a contract they are currently living at his home, his mom is there during the week to help get them to and from school since he works long hours. So basically his mom does everything(she just replaced me after the divorce????)