I quit about 5 years ago ~ best thing I've ever done.
If you think it helps you become calm, I have good news: Anything from breathing-technique to mindfulness will help you calm.
Why? cigarettes themselves don't calm the non-smoker, it does the exact opposite.
It can calm the regular smoker because his body is upset and in need for nicotine, once he gets it, he calms, but he wudn't even be in need for this if it wasn't for smoking to start with. see? so if it calms you, u're tricking urself, learn better way to trick your mind.
To be honest I'd smoke weed casually
cheers have fun with company