I got my DSM-IV out for you guys.

I would be inclined to say your problems and symptoms could be drug-induced as pachyderm said. Not only that, but it may not be schizophrenia but a related disorder.

"I'm 19 and I've had anxiety and depression for the majority of my life... my mom is bipolar if that's relevant."

If you are at a higher risk of an affective disorder because of family history and your own history then I think you should also look at other possibilities - Schizoaffective disorder, for instance.

Referential delusions are relatively common in schizophrenia; referential is basically believing "certain gestures, comments, passages from books, newspapers, song lyrics, or other environmental cues are specifically directed at him or her". I've heard of a lot of people getting messages from television shows, for example.

Most of this sounds like sporadic incidents of psychosis versus an episode which would indicate a potential to build up into an episode if the symptoms are escalating. It could very well be the onset of something, schizophrenia or otherwise.

Either way, go see a doctor because we aren't doctors. A psychologist can diagnose you (in my opinion better than a psychiatrist) but a psychiatrist is able to treat you medicinally as well.