Instead of trying to help the sociopath — accept that you can never help them. They will never change. And take the necessary steps to protect yourself and your family.
Your only option is cutting off all contact - NO MATTER WHAT.
So what do you do when you share children with sociopath. Are you forever fucked? Are you going to be miserable the rest of your life?
This is from my personal experience of sharing children with a sociopath. It has been hell. I do not get to enjoy my children. I don't get to feel happy about getting my children. I worry before it is time to get them because I have no clue what the sociopath has in store for me.