update- after thinking and worrying and wondering all day, i have come up with another possible cause. his ornaments! >_< i felt like each one was soft, and most i checked on nylon. but most were not actually made for bettas, just seemed to work. i feel really awful now, but i immediately took out everything that might have caused it, then added a silk plant in because it was pretty naked. i need to get to walmart asap for some salt and the same big soft rubber plant i keep in my other betta's tank, but with today being thanksgiving, im not sure black friday crowds will even allow the trip.
he does not seem to be sick over it, and is actually playing in the filter right now. in case anyone is as worried sick as i was all night at work