Committed A Crime As A Child

Tl;dr: I committed a really awful crime as a child, my abusive husband is the only one who knows. Wondering if I'm stuck with him forever now.

I committed a particularly horrible crime as a child. I can't confirm how old because I have very few memories of my childhood and everything is mixed around due to abuse (and have damage to my temporaral lobe, causing TL epilepsy, further damaging that area, due to the abuse). Probably somewhere between 11 and 13. I am currently married to and have children with a physically and sexually abusive man. I haven't been able to leave because I'm terrified he'll use his knowledge of the crime to take the kids away from me. The kids don't even want to be left in the same room as him, much less live alone with him, I don't want to risk sentencing them to that fate. They're all very young, under 5, so their feelings about placement wouldn't really matter as far as I'm aware. My question is, can he (successfully) use the fact that I committed a felony as a child to take my kids away if I tried to leave him? Or, I guess, is there a good chance of it working?