I don't think the earbuds idea would work, because of you shouting right at him such extreme words.
I would be mortified also, and I do think it shows how much you are struggling with whatever has been going on in your life toake you react this way. No its not OK to be beeped at by a man as a women walking along/crossing. I had wanted to hurl abuse at abusive people but it never achieves anything does it? You can end up in big shit, road rage incidents and so on.
I also don't like using negative female insults, it really doesn't help the rest of us women shed these feminized insults. That being pretty much one of the most hard hitting to many.
I don't know, its hard to tell, how close he was to you as you stepped off the kerb, but it was a polite way of saying 'look the fuck out' that could well be his perception.
It could be a case of so many things that we can conjecture about and still be totally wrong. Speak to him, show some humility about your extreme reaction, but ask him why he beeped...he may have been scared you hadn't seen if he saw your head down at that point he beeped, as this is what I get from your post.
He was smiling and jovial you were screaming extreme insults, speak to him about it, whatever either thinks it comes across as the decent and amiable thing to do. His being your boss shouldn't have any sway, or its sounding a bit oppressed