To see if someone is stalking you:
1. If you’re in front you detour, if possible, and keep going.
2. If you’re behind you stop and see if the other person also stops.
What the OP described seems like stalking to me. Especially the cussing. I didn’t read where the OP was “closing behind”.
I’ve been stalked. Took me awhile to figure out it was so. I was on the road and dropped into a line of trucks and stayed there. The perp saw he’d been made and left.
No people should have to fear the will of their government; all governments should have to fear the will of their people.