You have my sympathies, Hakan. I too have seen people I care about destroy themselves with drugs, and I have seen how much it destroys communities. It is inherently evil, like all drugs which destroy people.
I don't really have any hugely relevant advice to give on how to help people who will not help themselves, except that sometimes, only dramatic action works (in one case in my experience, I rounded up a couple of my lads, got my mate away from destructive influences up to the country, and had "words" with his ex supplier that in no uncertain terms it would be better for him to disappear, if you get my drift. That worked on one occasion, but it won't on many others.)
Simply legalising everything is no answer. People would still take them, and these drugs destroy people. Utterly. Just changing who they buy it from will not alter its addictive nature, nor their want to take it. It may alter its purity, or give people a nice clean facility to whack up in, but it does not change the fact they are doing so, nor solve the problem. Crime and gangsterism did not disappear when Prohibition was repealed; it moved into newer and more destructive substances. The drug trade will not cease; it will find something new, and always stay one step ahead. Appeasement and giving up is not the option.
I do not have the time at the moment to fully go into my thoughts and proposals for this matter, but suffice it to say I am against drugs. They destroy people, making individuals and societies weaker