Stimulants are certainly not the answer and could very well exacerbate these issues, particularly during the comedown period. Modafinil has compounded my depersonalization, which was brought on by psychedelic and, in particular, dissociative use. Marijuana often makes me feel depersonalized as well. Strangely enough, even meditation has caused bouts of depersonalization for me. There are some studies that suggest that meditation can precipitate underlying schizophrenic issues; I am not sure how closely schizophrenia and depersonalization are related, but this suggests that meditation is probably not the best for people who are suffering from mental illness, including depersonalization.
For me, the symptoms of depersonalization include a feeling of being alienated and out of control of my thought processes; "I" feel like an external observer to what is occurring and happening to me. In my interactions with people and my daily activities, I feel more like an actor than a conscious agent; I do actions that are appropriate for the situation but which seem artificial and divorced from reality. Could you explain more of your symptoms and what exactly you mean by 'depersonalization'? I cannot offer more advice than the obvious: exercise, proper diet, fun and new experiences to keep your mind limber, activities that limit stress and anxiety (as mentioned), and, if the situation is dire enough, psychiatric help or CBT. Blessings and good luck.