You might want to see if the police can help---have a chat with him...he is harassing you.
If he calls again, you could a) hang up immediately & block the #, b) tell him you will need to talk to the police, or his wife if he calls again, c)....
if you aren't going to forward the texts, erase all and answer none.
Be consistent, be unavailable, don't try one thing and then another---
You could still change your number, it is a pain with work, but you can.