Sex during flatline. Help

Monday of last week(May 1) I got asked out by another foreign exchange student - who attends a separate high school - to prom. I was at my longest streak so far of no PMO hard mode(30 days +) and in what I believe is, and was, a flatline. I had virtually no urges worth mentioning, and I went days without even considering PMO during that time.

Fast forward to the day of the prom and we're having an absolute blast. A leads to B, B leads to C, and eventually we end up having sex.

Looking back at it now 2 days later, I've probably never in my life been more high on dopamine than during those hours. I felt like I was in constant euphoria and we were both genuinely craving each other while also having fun....
Even when I could barely stay hard...

I know for fact that I did not have anxiety, and thats even considering the not so optimal conditions we did it in(not that relevant), but nonetheless, I was unbelievably turned on. Luckily the lack of enthusiasm in my genitals did not ruin the sex itself as I somehow pulled through, but I was hoping that my PIED symptoms would not resurface again, considering that is why I initially started my nofap journey.

So that is where my problem lies.
Did my flatline impair my ability to get hard even during enjoyable sex, or is my PIED still the problem?
If anyone has an input on this from maybe some similar personal experience I'd love to hear your opinion on the topic, as I feel quite bamboozled at the moment.