I've been hooked on opiates for 15 years now. [...] and my morals are still intact
These two things don't go together. You may want to re-evaluate. Get real help and free yourself.
Different person here. This is in line with my own personal morality and absolutely correct. My life is mine to do with as I please. I am free to do whatever I want whenever I want, provided that the consequences are SOLELY confined to consenting adults (generally that would be just me).
Anything else is an evil desire to control other people, with the approval you get from your own conscience, by convincing yourself it's for their own good, so you can pat yourself on the back and feel like a good person. The typical lack of reasoning ability, wisdom or long-term thinking in most people today and the general shallow thinking of the popular culture sadly promotes and legitimizes this inability to be satisfied with one's own life while respecting that others will live theirs as they please and realizing that telling people how they should live has never worked in the first place (c.f. Prohibition) so there should not even be a debate about this.
Someone who cannot responsibly use things (usually due to either a lack of personal maturity and self-knowledge, and/or an inability to deal with one's own life that causes them to reach for drugs as a quick-fix "remedy") has a problem. There are many others who use drugs the same way you might come home from work and drink a beer and stay home. Like Bill Hicks pointed out, it sure is strange the way you never hear about responsible drug users on the news or see them portrayed on shows. That would contradict all the fear propaganda and think-of-the-children rhetoric. Pay attention and you'll notice that the major mass media outlets will generally never contradict either: each other, or anything that faciltiates control. Adult people who are expected to make their own decisions about their own lives in a responsible manner, without being told how to live, absolutely does not facilitate control. Qui bono?