I agree with SweetCrusader highly (and I also am not qualified to give legal advice).

Document everything, save it and date it. It might be good to lodge a complaint against him, even if it doesn't result in anything, just to have on the record, but be sure to lodge a complaint based on evidence so there is no chance of him claiming that you are harrassing him by lodging false complaints.

My gut instinct tells me not to try to contact him to resolve the matter. There is obviously something going in here that is distorted in his mind, and any contact you make will likely be distorted as well... possibly good or possibly bad, but why take the risk? Then again, even if it does "resolve" the issue, this doesn't sound like the kind of guy you want to be "enamoured" of you any more than you want him as an enemy. You want him to forget about you.

You can talk to a lawyer just to see what possibilities you have. A restraining order won't do much good because it is not "proximity" to you that is a problem (that is a good reason to keep documentation though, in case that step is ever necessary). But maybe he will have some other ideas.

Can you talk to a therapist again, maybe that same one, tell them the situation didn't go away, but instead it got worse? They might have some other ideas of how to proceed in a way to cause the least amount of damage to both yourself and to this guy.