Wow, I heard of a bacteria infection (I think) that causes bloating as the primary infection and fin rot as the secondary. I will look it up. Hopefully you can find some saltwater Maracyn II in the area and have on hand just in case. Its good stuff and you can combine it with Maracyn for double the meds. But read in the instructions with combining meds. You can also leave the carbon while medicating if the carbon is more than 6 days old. Somehow, it has less affect on the medication after that many days.
Hang in there, you'll get through all these issues.