I've answered the PM.
For the thread though, ALWAYS call 999, do CPR (if you are willing, able and safe), administer naloxone if you carry it and are trained and safe. There is no harm to these actions and I've seem people brought back who looked dead to my non-HCP assessment. Breathing is very very slow and shallow, pulse too, cold, blue lips and unresponsive. Unless you're a paramedic and know the person is dead, you should assume there's a small hope.
On the discussion of which drugs are 'worse', there aren't better or worse ones. Alcohol; many people enjoy it safely, it's also the only one which can be fatal to withdraw from. Coke; it's not physically addictive but it's dreadfully psychologically so. Heroin; people tend to compliance and calm when using, but the crime to fuel use is terrible. They all have 'good' and bad qualities.
How I think of it is this: some people have a hole inside them from trauma or pain. Some big, some small. Sometimes that hole is partially or fully filled with family/love/work/purpose. Sometimes it isn't. Along comes a well-designed and addictive drug. The unluckiest people have a big hole, that is not filled with other things and the drug perfectly and exactly fills that hole. Sometimes the drug they try doesn't exactly fit the hole, which is why people may love heroin but hate cocaine. Detox can lever out the drug (assuming the fit isn't so perfect there's not a crack to lever it out). So the person 'gives up' the drug. But the hole remains. Therapy, treatment and hard work can help reduce the size of the hole. Finding a life after drugs can help fill the hole. But the person is never responsible for the hole. And if you've ever tried any drug (including alcohol) and didn't feel warm and whole and happy and like you came home, you are lucky. It's not a will of iron, or self-control, or because you're so wonderful. It's because your holes and the drugs you try didn't fit. Or you are lucky enough to have a good life filling those holes. Or you had a good childhood and don't have holes. Or your personality and the trauma you experienced didn't make big holes.
Don't lie to yourself that you would have been 'strong'.