I think everyone can relate to what you are going through: a bad gig can ruin sleep while you replay the tape over and over! Bad gigs are just that, one gig! There are no do overs and I"ll bet you are thinking about it more than others.
I agree with the others, play another gig!
If you believe the intro is not quite under your fingers, practice. If it is well-known and a one time event, no big deal. We don"t carry malpractice insurance for a reason.
I have seen Grammy-award winning artists do the same. Hell, I witnessed Steely Dan train-wreck an intro and stop a tune cold once. I saw Peter Gabriel lose his place during Solsbury Hill...you are in great company. It feels like crap, and this too shall pass.
Thanks for sharing and welcome to the forum.