I am really sorry about that. My fish are just as high in the rankings as our other pets to me; the people who see fish as minor pets, are the ones who don't know how to keep them alive long enough to get attached, usually.
I am not sure, but those symptoms sound like a swim bladder problem.. though, I am not sure how bettas work internally, as they are labyrinth fish. I had a goldfish for years (she was a huge telescope eye, even bred for me) and she started doing that; I was meaning to euthanize her, but she died by getting stuck between a plant and the tank side; just couldn't get free.