[forinti]

I could only conceive this behaviour as rational (although still uncivilised) if he wants to fire you and cannot.

In my country this sort of thing is illegal (work harassment).

[twoquestions]

Listen to this person OP. If your boss really felt a tenth of the things he says about you, he'd fire you and forget about it. Knowing nothing else about you, his treatment alone says you're worth much more than $40k, and I'd bet the house your criminally abusive (seriously, talk to a lawyer, slurs like this aren't kosher even in the US) boss knows this.

I'm sure your HR department would also like to know they have a sadist working for them.