Very scary, you had good instincts. It really stinks that the police didn't take you seriously. Perhaps a call to a superior officer might be in order, especially since this happened again.

I do carry pepper spray, but it's mostly for stray dogs or other animals on rural roads, if I get out on the dirt roads I pull it out of my bag and clip it someplace with easy access. You need to know how to judge for wind direction to avoid hurting yourself.