Hi , and I am sorry the stress in your family is so hard on you right now. Yes, and illness can be made worse by stress. Just don't let it become permanent and you can still move forward.
I cought my son when he was 16, the same thing. he asked me point blank,"what are you going to do about this Ma?" I actually let it slide, as what can I say when I was a child of the 60's? He grew out of it, joined the Navy, and to tell you the truth he was not damaged by his little adventure any more than I was. I am not saying I condone it, no, but in some instances, getting all upset is not worth it. If he is still stable, does good in school, handles his responsibilites. I would hope it is a passing phase that you can discourage without the whole family being in a uproar. Tell him your reasons you don't want him to do that calmly. Do not condone it, but rather talk to him about it not being good for his health in general. It has all kinds of things in it that can damage the lungs like cigaretts. My son never did go on to any stonger drug during his high school years, and of course never did it in the Navy. I never did eithor, and I don't now. Maybe just a good talk would be good in a loving way. I do wish you and your family peaceful times to come. Life is tough anyway. Take care, ginnie