Ok, so I'm really concerned. Roxanne has been very active in his new tank, but just a few minutes ago, he was just floating at the top of his tank, and I thought he was dead

I attacked his tank (viciously tapped it) and he didn't move until I almost shook the tank. So he finally moved, and then he just sat on the bottom. Now he's moving around a little more, but he still seems kind of still. I think he'll be ok, but I'm afraid that I'm going to wake up to a dead betta in the morning.
Ok, so also... I was over at my friend's house today and I think her fish has swim bladder disorder. Her fish (Kurama), sometimes leans to the side when he swims and whenever he tries to go to the bottom of the tank, he floats back up. She's tried the pea a few times and she's seen his poop, so he's not constipated. This IS swim bladder right? And from what I hear there's no way to cure it right?