I am having the same issues with my betta, she was bloated from overfeeding (I'm learning) and then I unknowingly over-cleaned her tank and I think it caused her stress. The next day she was doubled over and floating. I tried the fasting, the pea, change in pellets (she won't eat pellets though, only likes flakes).
Finally found this thread and bought her some frozen daphnia. I am very interested in trying the epsom salt treatment, though I am having trouble finding it. Where does one buy epsom salt, assuming it is different than aquarium salt? Are there any special instructions to using epsom salts to treat Swim Bladder? Because her issue is stress-induced, is it a good idea to treat with salts? I've read mixed things about this treatment causing more stress for fish.
Any advice would be great! I'm learning as I go, but I would do anything to save my little girl!