Sorry about your drug problem and all, but in reality the majority of people who try heroin do not become frequent users or addicts. Letting people know the consequences of addiction is great but I strongly disagree with things like "the shit will turn even an angel like person into a fucking monster", "it will slowly rot every good thing out of your life" or even "snorting, swallowing, and everything else is just as bad and WILL end up with a needle in your arm". You make these out to be definitive examples of what will happen if one were to try heroin, they are not. Rather, they are things that might have happened to you or other heroin addicts.
Heroin will not turn a person into a monster, drain everything good out of someones life or force you to stick a needle in your arm because when it comes down to it heroin is just another substance. Physical addiction is the result of a conscious decision a person makes to repeatedly use a substance. What I mean by this is basically that the heroin does not keep putting itself into a persons body and using heroin once, twice, even three times does not instantaneously turn you into an addict.

I have used heroin five times in my life. Never stole anything, never lost my friends, job or self control. Never put a needle in my arm.