Questions for those who've relapsed after a long streak

Relapsed after 120 days. Made a separate post about it if you're interested.

Anyway, I have some questions for those who've had a long streak and then relapsed.

How did the relapse change your willpower? How did it affect the progress you had made? How much of an impact can one session after 120 days have on one's progress with, say, PIED?

Most importantly, how did you bounce back?

Thanks.