So, a little bit of a back story here.....
With the exception of my two females(Jinx and Tetsuya)All the fish that I have in the RIP part of my siggy died in one of my two 2.5 gallon critter keepers. And now Shiro-chan is suddenly lethargic and refusing food :/ GAH! I don't understand!! No one seems to last longer then a month in my critter keepers, every one that died obviously died of something different too. I can't see what I'm doing wrong, I keep up with my water changes, they're fed the same things as my others in the cycled tanks.....I don't understand. :/ After each fish had died, the keepers and decor were rinsed thoroughly with hot water and then left alone, nice and dry, for at least a few days....and, like I said before, each betta has had something different....so I am TOTALLY stumped. >_<;
It can't be my water either, Max has been in an uncycled 2 gallon tank the entire 6 months we've had him and hes thriving, though hes not in a critter keeper.....I just really want to hit my head on the wall repeatedly right now :/ If Shiro-chan dies, I'm debating on either throwing the whole thing out or just giving it all a soak in bleach THEN vinegar THEN bleach again >__<; Ugh......
Anyone? Help? :/ I'm at a complete loss and I'm desperate, it wold just kill me to loose my precious Shiro-chan

......I'll do ANYTHING.
As far as his symptoms and everything...
This all started out yesterday really, I found him laying on the bottom and hiding behind the heater(temp is a steady 79-80 degrees, theres no way he could be cold.....)as opposed to swimming around and hanging out in the front of the tank, watching me. He just had a WC the night before, so his water was nice and clean. He spit out breakfast, spit out dinner, and doesn't even try to eat today :/ I changed his water today as well, rinsing out everything in hot water, replace it and accumulated him....no difference. And now his fins are clamped and hes flashing

UGH!! I don't understand! Physically, he looks just fine, and he still responds to me peeking into his tank....but then when I lean back he goes back to this odd behavior. Is there anything I can do? Anything I should try? ANY suggestions at all? Please....I'm desperate...:/