You're a idiot for sleeping with prostitutes while dating somebody, if you've got your widdler in somebody else, yeah that's cheating.
Go jack off or something instead, watch porn. Just don't go and have sex with somebody else claiming you 'have needs', you can last a week, don't be a ****.
And if you feel the urge to run around and sleep with other people so often then clearly you shouldn't get into a relationship. Sleep around until you ARE ready to be in a relationship, because all you're doing at the moment is screwing with them and wasting their time, it isn't fair.