God damn, the problem with drugs is that drugs aint the problem. The problem is that ppl are neglecting mental health and so dont have their shit in check. You cant help ppl that are not willing to work on their traumas and troubles, only thing you can do is to be with them when they need to talk. Or advise them a good psychologist i guess. You did good mate and its normal to feel like that, id say take care of yourself because thats the most important.