self destruction

I'm honestly grateful that in all my past of self destructive behaviour I was able to stay away from the hardcore addictive drugs.
I'm sad to say that I am watching a repeat happen of one of my family members being addicted to drugs and the stories, or bs that comes out of her mouth I just wonder if she knows what she is saying to us?
It's so terrible to watch her destroy herself and be absolutely helpless, voiceless, theres nothing I can do or say that would make her want to change or seek help. I basically have to stand by and watch her go through this. and be consistent in my "tough love" no I'm not giving you money, and no I cannot do this that or the other thing for you.
I worry about her the way I worried about my older sister... and now because I work in the dtes, I am always aware of what's going on, and who's what where when. and there are a lot of terrible people int he world, and they go downtown looking to cause harm.
the hardest stuff is recently finding out that Heroin which is a highly addictive drug, when I was a teenager I read all about those drugs, the effects, and the withdrawal etx. but I haven't done that in a long while, I wondered how long it lasted like the high lasted.. and I was surprised to hear or read it says like 30 mins! so someone has to spend 7-15 dollars every 30 mins just to maintain their high, as well as I'm sure they end up upping the dosage through continued use which means more money!
how does anyone be able to support their habit? I understand stealing and selling stuff, or begging for change, or collecting bottles, but how does anyone want or desire or need to go through that.
I feel like I've seen my sister hurting for dope more than actually doing it.. and even in her lowest of lows she won't seek help, and she believes that we (my family) is all here just laughing at her failure and I thought.. why would we be proud of something like this? we are all feeling like we failed, or something because she just started this heroin stuff a year ago, an now its completely out of control and destroying her life.
you know I hate the way she is now.. it's like not even knowing who she is anymore.. I wish I could help her, I wish I could get through to her. but I can't. I just I'm completely blown away that of all things that she could have done she did this!
I guess her feelings of abandonment were real, and her then boyfriend told her to do the drugs, told her if anything she should do them while he is doing it. and then they broke up and he's not doing drugs, and she is completely lost in those drugs.

I don't know what to do.... I don't know what to think. I'm worried, scared, and I don't want to lose my sister. I just wish there was something, or someway of getting through to her.. besides just standing by and watching her go through this.

thats all that Im gonna say