Hi pumpkin, welcome to PC!!!
You know it wasn't good that you showed your coworkers the photos, and if you could take it back I'm sure we'd agree that without a doubt you should. Although you can't...........but by doing that it has probably helped you to see your sister in a different way, which is a positive, right??
I mean you've clearly seen the basic respect, human decency, empathy that she deserves regardless of any other circumstances.
And you know you should really credit yourself for recognizing that, because I'm sure there are a lot of people in your position who might never come to that sort of understanding .
So you know, well done!!!
So now...........do you think you could use some of the depth of that insight, and make it work for you/for her???
It does sound like she's really struggling, and of course some of her behaviors may as much be a reflection of addiction (which can be so powerful!!) and the behaviors addiction have driven her to instead of her.
And obviously I don't know what might be possible, where she's at..........but you trying to help/support her could range from anything between looking up programmes that she may gradually come around to considering, to offering her a little help if she needs help with something (not giving her money though!!!), to trying to talk with her a little more, to talking to her more empathetically when you do talk to her.
And even if you can only manage the last then sometimes when things are dark for someone just knowing that someone values them, treats them equally without looking down on them, listens to them, understands/cares can be a big thing.
If she's too angry at everyone or you're at risk of physical abuse then it might all turn out impossible, but at least you're going to know you gave it your best shot and from a position of seeing her in a different way!!!
Perhaps as well check out the addictions forum on here, because there are so many misconceptions spread around about addictions:
Addictions - Forums at Psych Central
And the guilt...........well there's no way of changing what you did so perhaps see it as something that led you to some real enlightenment.........and enlightenment has to be good right?? You have learned a lot from what you did!!!

Alison