You are not a bad person at all.

I think that your family cares about you a lot but they are showing it in all the wrong ways unfortunately. I do not think they wanted to make you feel terrible about yourself. My guess is that it probably came as a surprise to them that you have been smoking and they dealt with it in the wrong ways.

My suggestion would be to take some time and think. Try your best to figure out where you have hurt them and take responsibility for that.

And they need to take responsibility for their behavior too, don't take that upon yourself, let them figure out that they have hurt you too.