It is very good that you are trying to stop smoking, and that will benefit your overall health. The green tea used in this fashion may very well be causing your stomach and digestive problems.
that definitely could be from somking the tea. I used to be a pack a day smoker myself, but now im down to smoking 3 or less a day from using an electric cig. you should try that instead if your having pains like these.
First, congratulations on trying to stop smoking.
I think that trying to smoke the green tea is definitely having a bearing on your tummy pain. I would stop for awhile and see if it goes away.