Lewdatic

A person who is so preoccupied with sex and/or his or her own sexual desire, they are considered insane by others. This can also be said of such a person about themselves because they themselves are so sexually preoccupied and think something is seriously wrong with their sexual desire/tendencies and something needs to be done about it ASAP.

A: Pedophiles are a one of a kind lewdatic.

B: I want to quit looking at porn. I feel like a lewdatic.