Question about the health of a 5 year old angel fish?

I've had an angel fish for about 5 years and he's always been healthy. About 5 days ago the angel fish started floating totally sideways and both of his tentacle like fins (which were 4-5 inches long) were suddenly gone, even tho he was the only fish in the tank. Because he was alone in the tank i umed he was about to die. Now, 5 days later, the angel fish is still alive. I've researched and can only find "swim bladder" as an explanation, but only on the side my angel fish is floating on the surface is there any bloating present, since bloating/swelling are common parts of swim bladder diseases...on another site I saw that raw frozen peas can be thawed and skin removed and then fed to the fish to help them recover, but are there any other suggestions for my poor angel fish? I really don't want him to die since he's my only fish... btw: tank temp is about 75 F, and No salt.