I vote now as well.
He has a support system in there and it becomes his and Their responsibility not yours! First do what you feel you need to do in order to follow through with this i.e. phone or letter.(emotions yours) Which will make you more comfortable because it is not about him it is about YOU!
Then try not answering the phone when he calls because I’am sure with today technology you do know when it is him. (hard I know but if you are sure you want no contact it is a way to start)
((((TG)))))