I very much agree with susannah. The best approach would be to be thoroughly evaluated by a medical team - not just a psychiatrist but also medical tests in order to rule out other possible causes, as some physiological conditions that are not primarily psychiatric can also cause psychotic symptoms, as well as extreme stress, drugs etc, in vulnerable individuals. If alternative causes are ruled out, I would definitely start with a medication regimen prescribed by a psychiatrist, considering all known individual factors, possible dual diagnoses etc. And then (or simultaneously) maybe try a form of psychotherapy. I think there are quite a few people here on PC with schizophrenia, schizoaffective disorders, severe bipolar (which can also produce psychosis) etc who are on medication and also see a therapist, or at least tried different combinations of treatments. Definitely the earlier start of exploring appropriate treatment the better.