Some ideas, what I might do in your situation:

I'd keep a notebook going where I jot down times and dates of when I see the man drive by.

I would call the police, and make sure that if nothing else, they record the facts. In my experience, some cops aren't much help, but some -really- are, often they have even told me to "when in doubt, always call, we'd rather get a call that turns out to not be vital, than have you not call". Even police that aren't helpful can be guided to do their jobs, to at least make things official.

I'd work on therapy about how the word -crazy- is being used in my life to intimidate me, I'd work out ways to come through that. For instance, even if I was "crazy", even if I was the stereotype of a Hollywood film raving lunatic, I still deserve to be treated well, I do not deserve to be abused.

If I could at all arrange this, while parents are gone I'd see if I could get out of town for a week or so, if that would be helpful. Stay with friends, or if I could afford it, go on a brief trip, stay at a nice hotel.

I'd also plan out with my T how I'm going to survive the month while supportive parents are gone. I'd write things down, post a reminder on my frig.

Oh and I'd make sure to eat well, reward myself somehow, and do whatever fun things I can think of.