Are you on medication or getting therapy to help you cope?
Which symptoms do you get daily?
Depersonalisation is very common , it's one of the most disturbing symptoms of anxiety.
It's also a symptom of migraines so it can have a nurogical cause .
If you are suffering this much do you think a nurologist could reasure you?
It would be good to have everything ruled out.
It does seem how ever to be anxiety which might have been induced by the drug use.

Have you posted on any other forums ? I know they are a few around that deal with the aftermath of drugs use, not sure of the names though.