my ex would eliberately mistreat his and their diabetes. All diabetics can have occassional control issues, but the timing of his were predictable and telling. He always had a seemingly reasonable excuse that people were willing to accept and see him as the good guy and me as a mad conspiracy theorist.
He hated me getting therapy, so he would cause himself to have a hypo so I couldn't leave the kids. He also over injected them when I had began to put appropriate boundaries in place. My therapist helped me to see the truth and get through to SS.
When I finally got him out, he stalked us, turning up wherever we were. Acting like a kicked dog. He couldn't understand why. Threatening suicide which he never did successfully but he made surethatthekids saw the blood and knew it was my fault. All despite a non molestation order. All that mattered to him was his position of power over me and them.
So a year ago I put my foot down and made the decision that he would not have unsupervised contact. I had the psychologist report to back me up. I welcomed him to take me to court, but he never did. SS would pressure me to allow the kids contact but he never organised it.
A year later, there is no SS involvement, he doesn't see his kids because he says he can't afford to. They get so many presents from him delivered by relatives. So do i. He is still hoping to drag me back under, but he won't go via the court because I have evidence.
Keep a journal of everything. And do everything you can to keep them safe.
You will get a lot of people telling you that they need their dad. A well functioning mum is better than a half mum and psycho dad. Every time.