She tells me that “I need to be more professional… give me a break!”

I need to process something because I genuinely thought I hallucinated this. My supervisor came to session yesterday. She walks in holding a SUPER BIG GULP—I call it a keg of soda—and a FAMILY SIZE bag of Cool Ranch Doritos tucked under her arm! It gets worse. She plopped down on the chair, opened Netflix, FULL VOLUME, while I was struggling with the session. Crunch. Crunch. Crunch.
I’m trying while Dora the Explorer is yelling in the background and Cool Ranch is aggressively existing. At one point she actually says, without looking up from the screen, “You might want to prompt more.” Ma’am, you are watching Netflix in the session. And when the client elopes toward her, she just lifts her feet slightly so he doesn’t step on them and keeps scrolling. No assistance whatsoever.
Then afterward she tells me, “You need to be mindful of professionalism.” Initially I thought she was joking; it was like The Twilight Zone. I’m sorry, I have had it! Like bringing a gas-station chalice of Mountain Dew and a snack bag large enough to feed a middle school basketball team into a clinical setting?? She also commented that I “seemed slightly flustered during challenging behaviors.” Slightly flustered??? Yes, because I was single-handedly managing behaviors while my supervisor live-streamed snack time. If you’re going to supervise, supervise. The irony is WILD.
I am begging for mentorship. For guidance. For actual feedback. I’ll work on my professionalism… jeez, not sure this field is for me anymore.