I have a nut job on my route, have called postal inspectors on him 7 times. I always knew he was flakey and exhibited behavior I found annoying and unacceptable, but one day delivering a numbered insured to his secluded lake front home, I thought my body would eventually be found in the pond when it escaped the concrete and floated to the surface. He was acting stoned, did some odd twitching as he started at my chest. He didn't make much sense...
I told my boss about it, one of the city peeps heard and told me to call postal inspectors. They spoke to him, gave him no contract order, told me mail to box only, write up anything else. I also called local police to apprised of situation, so if I needed to call 911 they would know what was happening. Since then I've called inspectors 6 more times, once after he chased me down the road in his pick-up after I delivered his mail.
They never put him in jail or prosecuted him. (Retired state police on my route say they're waiting for him to put his hands on me. I will do what is possible to prevent that, and if necessary will throat-punch him. I'll be damned if I let my family wonder where I am for years while they look for my remains, killing me a thousand ways in their minds trying to figure out what happened to me.) I may die there, but that is my choice. This flake thinks all women are stupid, so that's to my advantage.
I keep a running log of what he does, in my locker, as some of his harassment doesn't cross boundaries set up by postal inspectors. I researched stalkers online, and warned everyone I knew not to tell this creep anything about me. THAT'S when I discovered he had harassed one of our window clerks while she was detailed out to some tiny offices in the sticks. (I drive by one on my route) He found out where she lived by talking to another clerk, saying he was her friend, etc. She never reported it.
All this cr#p started escalating a few months after my husband passed away, while my PM, now poom, was harassing me because it took me 9 hours to do a 9 hour route with uncredited Amazon. Oh yeah, I'm step 12.
Advice? Call the cops, make a report and press charges. You were assaulted. Don't beat yourself up because it shocked you, that's normal. Call 911 if another problem. Postal inspectors will keep you on hold for 15 minutes and are not first responders. Mentally prepare yourself for various scenarios. My creep has a plan, I need some myself. Make a written statement for the postal inspectors and notify them yourself. (Second time I had to call inspectors my supervisor let a day go by without calling them. Yes, I was livid.) Keep a written record. Take it very seriously.
God Speed.