You may be self-medicating for an undiagnosed problem, if you're interested in being without vice/self-medication, see your doctor about alternatives.

What's sheesha?

hash.

Hash is clean, specially in oil form (if you can ignore the "junkie" appearance of carrying a hot burning knife and a plastic water bottle ;-)

Sheesha is hooka, tobacco smoked out of a water pipe.

Right, short for hasheesh or hasheesha. It's also another way of referring to hookah.