I am going through something similar. I have instructed a barrister who has advised me to stick to emails or messages no phone calls unless in case of an emergency.
I applied for a non mol order when it started however this was rejected by a judge who is very set in his ways and believes parents should always get along regardless of past issues. Explained this to barrister who said there is a clause that can be put into a court order to forbid ex partner from discussing anything other than contact arrangements in a civil manner.
not sure if you are yet going through court proceedings but if you felt a non mol would be appropriate it is free to apply for and the court could prevent him from causing any distress by verbal abuse.
hope this helps x