Hahaha, how amazing would being a sex therapist be!! Hmm... *ponders seriously as a career*
You're 16, it's probably just hormones making you so horny. If you crave sex several times a day, masturbate and watch porn excessively or go out of classes to masturbate then you're probably a bit of a sex addict. Or have a high libido.
Haha you got me thinking.