Augustine: If it were me, I would end his parental rights in court because he is not seeking treatment and is abusive. If he struck other people, he could do it to them. Hopefully, he will get tired of this and just do something else besides all these calls. I know of someone whose parental rights were taken away for this very reason. Get whatever help you need: Food Pantry, Govt. subsidized Day Care, many ladies are job trained to help the elderly with errands and cleaning in their home. Our daughter and I learned not to depend on the ex for anything. I had a Grandpa who was abusive and he took me out of his Will for not bringing my daughter to him - good, she did not have to go through what I did. Nicole?
Sounds like you're on the right track -- limiting exposure, not taking calls. Don't delete texts or email -- just don't read them. Save them for your attorney.
Don't forget to document everything he says or does in your own notebook, courts and lawyers like it when things are spelled out and clear. Call the cops if he continues to verbally harass you so you have that documentation as well. Police reports of some kind are good documentation -- means you're serious when it comes to following through and protecting the kids.
Heck yes to contacting your local or the national domestic abuse hotlines. They are the experts when it comes to leaving an abuser and what you can do to protect yourself further. don't hesitate to find out what it takes for a restraining order/order of protection in your area -- the cops may help you with this, if not they will know who you should contact about it.