Your entire argument is pretty flawed
First of all, not every single drug user is an addict that rapes kids whilst high on PCP and crystal meth. It's simply not true. Now I have no basis for this, (yeah, discontinue reading from here on until my next paragraph) but I'd posit that most users of recreational drugs are exactly that. Recreational users. They aren't addicted, they aren't dependent upon it and they aren't (too) destructive to themselves, their loved ones or society at large.
Another thing that you said is that the government should supply it, which is not what users here would support. I would much rather a private enterprise that will be held accountable for its product and its profit and, equally as important, its losses. A private company working in self interest with the profit motive will provide superior narcotics at cheaper prices. You'll probably not have any of the fucking horseshit that goes into pills and junk as well. Of course they will definitely have to follow some pretty stringent guidelines and practices. Like not putting shards of glass in their products.
You're also saying that if something is now legal, there will be a huge flock of demand for it. That's not entirely true. Usually there is no real change in the demand because quite simply the demand is already being fulfilled. People who were using it before legalisation are merely going to continue to do so but the state won't put them in rape cages with violent criminals for it anymore. You might see a small spike in sales, especially since they can actually be recorded now a lot more accurately, but this may be due to current users increasing their short term demand since the price will have dropped so dramatically.
Decriminalisation at the very least is not a thumbs up from the state to go ahead and get high every 30 minutes and then fuck your neighbour's dog. That's not how society works. Society works in a social way (derp), not a coercive way. People won't do drugs because it affects their health, the same way people don't smoke and drink or have unprotected sex with strangers. They will also not do it because they think it is something that is 'beneath' them (or something along those lines) and through the processes of social interaction, people can more or less ween their communities off of drug use if users are ostracised for their actions. Now if there is a choice between merely excluding someone from social gatherings or invading their house, kidnapping them at gunpoint, throwing them into a cage with violent men/women for whatever length of incredulous time, I would choose the former.
I was going to include this part in the first response, but I think it's more fitting here. It's interesting that you harp on and moan about "the consequences" and "hurting people". You know the drug war in America has caused about 36,000 deaths right? You know criminalisation of substances gives root to black markets that enforce their trades with horrendous violence, widespread corruption, extortion, rape and murder right? That's not even including what the state does to people (the same thing). You don't seem to realise that the consequences of legalisation are that, yes substances are more readily available for immediate consumption for people, but that it relinquishes the cartel's vice-grip on force, innocent civilians and allows violence to diminish on a wides scale. It might take a generation to see these monsters die off, but it will be worth the wait. Where would any drug lord who keeps his business in check with widespread violence get his power from if he can't sell his products at a marketable price? Free enterprise would undercut the cartels and we would see freer societies in South American nations because the cartels would lose their footholds in government, because they no longer have the funds for it. Without money, they have no power and without power, we have no violence.
So, as you can see, these things can spell life or death for people.
That's a really fallacious argument that doesn't mean anything.
"yo so like alcohol has a higher bodycount than anthrax, why can't I shoot that up at central station fuck fascism"
The analogies you're putting forth aren't the same to what you're supposed to be arguing. You're arguing whether the state should coerce the citizenry into following the majority rule on substance use. This is very different to them inflicting very serious, immediate harm on themselves. Before you say "rah rah rah drugs are bad mmkay", someone smoking a joint of marijuana isn't going to die from it, while someone who is opening their veins at the wrist with bladed instruments is very likely to. Like I said before, individuals, in their own self interest, will use social interaction and constructs to keep drug use down. I bet that if you ever have children, you will tell them that all drugs are bad and you should stay away from them (social interaction). That's not the same as putting a gun to their head every step they take throughout their life warning them off it (coercion).
A child committing suicide is not really the same situation dude and it's a pretty poor attempt to draw a connection.