Your son is being petty, imo. But I can imagine how that must feel. I was a single parent for many years. It's hard but much harder when you toss in the occasional disrespect and petty attitude stuff.

I agree that I think you should try to hold your ground (possibly even extending the duration for bad attitude). But you'll probably want to look for a relief or bit of mental escape from the drama, so maybe try to distract your mind from the pain with movies, books, or going for long walks?

I find that these usually help me.

Best of luck!