Freaking out… Should I be? *Please help*

I have two kids, their dad turned out to be really abusive. Emotionally, verbally, physically, sexually. Squeezed our son’s leg (newly 1 at the time) once in public. Our relationship ended badly and the last time I saw him, he put his hands around both my neck and nose and told me he’d cut off my breathing and was telling me about demons he had in his head, with our children on the other side of the wall. At the time they were a year old and 2 months old. Then told me that he would “track me down” since I wouldn’t tell him where we were moving. They’re now 1.5 and 2.5 and he hasn’t seen them, even tho he does has visitation rights, and I’ve had a restraining order on him. He’s been really behind in child support, probably about 6k? Then tonight, at midnight, I get a notification that a partial payment was processed. The only other time I got a payment was when they took his taxes. I’m worried that him starting to pay also means that he’s going to want to see them. And I would be really scared, already am. He always played games and I’m worried this is one of them. I just don’t trust him at all.