Why doesn't my body's adrenaline work where epinephrine will?

I’m curious about this. I have an allergy to tree nuts, and a few years ago I had an anaphylactic reaction on a plane after eating a sundae with what I thought were peanuts. (I know, a stupid assumption for me to make.) I recognized the symptoms immediately and stopped eating the sundae. Eventually, a doctor was called, and then they asked for a nurse when the doctor couldn’t draw the epinephrine into the syringe. During all of this time, my heart was beating fast and I was horribly embarassed. (I ended up mooning first class when I had to get a steroid shot.) So why didn’t the adrenaline from my stress do anything to counteract the anaphylaxis, where the epinephrine injection did? Or did my immune system override the release of adrenaline and I just thought I felt an adrenaline rush?

Your body produces epinephrine in physiologic (tiny) amounts. Your doctor administered a supraphysiologic amount that your body is incapable of producing.

That makes sense. I don’t know why I didn’t think of that. Thank you.