Any Advice?

I had a psychotic attack last week, it was provoked by mixing alcohol and  marihuana. I´ve been using weed chronically for more than a year now, it started when I was 15 and since last week I've noticed that my behavior and beliefs may be related to a psychotic disorder, I sometimes believe in things that I know may not be true, but it makes sense in my head, when I try to explain my thoughts to others they often don´t understant or don´t believe in what i´m saying.

A couple days before the attack I started noticing my way of thinking was starting to lose logic and coherence, because I saw plausible things that for anyone would be imposible.

I also am starting to doubt if these symptoms were actually something to worry about or I was just trying to convince myself, but I feel that the fact that I know I could convince myself of being insane is another clue that I could actually be insane.

...

I've stopped using drugs but I don't know if that is enough for the problem to calm down, I don't really want to go to a professional because I'm not sure if what's happening to me is really what I think it is, I don't see being psychotic as an obstacule, I can do my everyday fairly fine, but I'm concerned it might get worse... Also I have seen this psychotic symptomps in my father, mother and brother, it might be related...