Honest question, do you have an alcohol problem or addictive personality that is driving this fear? If not, what keeps you from drinking yourself to sleep on the sidewalk every night?
When it comes down to it, not all drugs are equal. Heroin isn't "alcohol but worse". People who drink tend to get pretty nasty sometimes, and that's a social harm that someone who's nodding doesn't perpetrate. And in terms of physical harm, heroin is actually pretty low compared to alcohol. Lots of people destroy their livers with alcohol and die early, while there's an awful lot of rockstars who do piles of heroin and cocaine and live to their 70s and beyond (we need to start worrying about the kind of world we're going to leave for Keith Richards).
The harm comes from getting bathtub stuff of uncertain potency and purity, and from the things people need to do to afford their fix. If it's clean and affordable you tend to do fairly well on both the 'personal' and 'social' harm aspects.
Obviously that's not how DARE told you to feel, but the fact is that the current state of things is not the only one that is ever possible. You don't know what social use would look like in a society with legalized heroin usage.
If you eliminate the need to commit crime to obtain black-market drugs at obscene prices, a lot of the harms of heroin go away. Some people will still choose to do it, but we free up a whole bunch of police money that can be redirected to free treatment resources to help people quit when they realize they aren't going to find happiness in drugs.