Hmm.. I think the pre-heroin consequences were fairly important: 1) he was very unhappy, 2) his family felt betrayed, and 3) he lost his ambition. I think it's impossible to feel addicted, like he was, and be happy -- and happiness is really all that matters, isn't it? (And he retrospectively describes himself as quite depressed). Besides, if he was checking himself into a rehab/detox program at the hospital, then he was not in good shape. Also, the family stuff, like you said, is important. And then his ambition. He didn't seem to really care how he did once he reached college, and his interest in writing seemed to fade; pot and alcohol seemed to become the focus of his life. That's an important consequence, regardless of whether he got some good marks.
It's hard to say whether he looks on his previous drug use in a darker light, now that he has recovered. He obviously thought there was a problem, to check himself into rehab. In any case, denying there is a problem does not necessarily mean there isn't one.
