I strongly recomend against the pricking with a pin. My mom's the equivilant of a vet and will only do that to a fish if it's dieing and pregent to save the little ones. You mentioned that this was a steady growth. I hate to say it but your fish is likely experancing some interntal organ damage that is retaining fluid and waste. This will lead to infections. He may not recover, but there is always hope. Put him in a smaller tank so he's not struggling to reach the surface should he be in pain. I don't know anything about epson salts, I see many recomend it on this site, but this is the only site I've been too that recomends them. Other sites have warned against it for Betta's, and said to use some speical aquiarum salt, so I'd ask a pet store first. Also, if you can do it without stressing out the fish, take it to the pet store and ask a rep. Or call them and describe the bubble on it's side. They'll likely say it's dropsy but I think it's more then that so be persistant. Try Jungle Parasite Clear fizz tablets. Use half a tablet for a five gallen, and 1/3 for a small, single/2 fish size tank with 100% water change and 4 dropps of water conditioner (small tank), 1teaspon for a five gallen (or whatever the instructions say). The parasite clear should help if there is parasites (most likely internal if you have them). If that cord coming out of your fish is a worm and not waste, it's likely a tapeworm. You'll need to continue treatment for a week. Ask a petstore rep or call the med's company before mixing treatments, natural or medical together. You don't want to cause further harm. Hope your fish lives, I'll pray for it.