I agree with everyone else. Don't be so hard on yourself. You, like all of us, are a work in progress. And you are a mom so you can't expect that you won't slip from time to time. Giving him cigs was not a bad thing; but I know you are much more mad at yourself for not being able to just "fix" what is wrong with him. I was like that for such a long time with my AD and I still inwardly wish I could just wave a magic wand and rewind the clock and calendar but I don't stay in that fantasy world for very long.
I've always told my AD that I would give her food, warm clothes and help her find a place to get help. Nothing wrong with that. The rest is up to her but I think I would even give her a pack of cigs!
Hugs,
Marteen