I think it was a combination of the marijuana (and withdrawal), lack of sleep, and my predisposition to psychosis/anxiety/obsession (I've had delusions before and they started when I started to smoke). I don't remember exactly, but it started after staying up for a few days after quitting.
I don't want people to connect DP to what happened to me (because psychosis and DP are two very different conditions) or make them anxious about going crazy.
I believe if I continue my sobriety I'll make a full recovery and won't have a need for anti-psychotics, though they are helpful at the moment...despite the side-effects.