Being an introvert is a vastly different thing from what OP described. Extrovert enjoy social interaction and need it as part of their "energy", while introverted people will see the same kind of interaction take a toll and thus need time alone. Carl Kingdom explains very will what introversion is about [1]. Also, remember that introversion / extroversion isn't a binary trait but a whole spectrum of behaviours. If OP lacks empathy and feels the need to exploit other people to his own benefit, then chances are that he has psychopathic traits. That doesn't mean he's a serial killer or that it should be taken as an insult. Of course he can have more information by consulting a licensed practitioner.

[1] http://www.carlkingdom.com/10-myths-about-introverts