You have to start somewhere and it seems to me that getting a restraining order is a good place to start. I am well aware of its weaknesses, you can't waive a piece of paper at someone attacking you. However, it will give you credibility if/when you need to call the police for assistance. Talk to an attorney and tell him your situation - see if he has any advise even if you have to pay for an hour of his time - although often attorneys initial meeting is free of charge but ask ahead. Don't cut down every option because its not guaranteed - it has a better chance of working than doing nothing. And if I were you I would have a handgun available for this nut or anyone else who might attack you whoever they are. Better to have one and not need it than need it and not have it.

One of my children has worked as best he can to deprive me of my handgun i got after a home invasion. He wasn't interested in helping me feel more safe. he was, I realize now, attempting to flex his muscle but he's not going to be a part of my life any longer and so hopefully his ability to be a 3rd hand threat to my safety is done with. DO WHAT YOU CAN. Do what you gotta do.