What are the laws in your state with regard to recording conversations? If you can legally record the conversation, I would call and then if he threatens your husband, you have some evidence to take to the police. If you can’t legally record calls without both parties being informed, could you have someone else present and put the call on speaker so again, there is a witness as to what is said? Is there anyway to trace your address from your phone number? I have an unlisted telephone number, so I don’t think someone without access to telecommunication records could find my address. I think your concern is warranted. You’re not overreacting.