There are several conditions that could lead to this feeling of constant hunger, everything from stress and anxiety through to prader willi syndrome. Each and everyone could cause all the symptoms of what you describe. But nothing we can say is substitute for medical expertise, which is something I think you really need to consider here.
...How happy is the blameless vestal's lot!
The world forgetting, by the world forgot.
Eternal sunshine of the spotless mind!
Each pray'r accepted, and each wish resign'd...
Alexander Pope "Eloisa to Abelard"
The iron ore feels its self needlessly tortured
as it goes through the furnace.
The tempered blade looks back and knows better.