Just a suggestion...
I don't for one minute profess to be medically qualified to say this...
I do profess to have myself been an alcoholic for 30 years, and in recovery and therefore considered by others and myself, not only to be safe, sane and sober, along with the fact that I've gained a lot of knowledge on both alcoholism, and related addictions in the process...including the fact that on the odd occasion, whilst drinking. I've smoked the odd 'spliff' myself.
For example, I know for a fact that long term use of marijuana, cannabis or 'weed' whatever you want to call it, induces feelings or paranoia...similar to the effects you're describing..
As to it's proper diagnosis and treatment, for that you'll need professional medical help, which is way above my pay grade, sorry.
Just a suggestion, hope it helps...