The problem is, once that seed of doubt about something you've said or done gets planted in your head, you're then hypersensitive to anything that might confirm the suspicion that you did something to merit yourself a total jackass. In this case, the fact that this friend replied to another friend's comment but not to mine was, to me, a sure indication that I sounded as idiotic as I fear. I've even checked my account two or three times since then in the hopes that he would at least acknowledge my joke with a 'lol' or even tell me it was lame; anything to silence my own doubt.
As of yet, I haven't been able to figure out a way to turn off these mental self-beatings, as unproductive, destructive and juvenile as they are. I understand - as a somewhat rational person - that even if I did make a comment that was lacking in insight or humor, it isn't anything to feel like less of a person over. Still, right now, my brain is stuck in humiliation mode and has no idea how to turn off the switch.