It appears she has a number of problems, and does, indeed, need help. If you are unwilling to be with this person due to addictions on their part, thats well within your perogative. I know bloody well that I was NOT dating material when I was in active addiction.
If you choose to contact her, and she accepts, how do you intend to "help?" If she isn't ready to change, you're only creating a mess in your own life for her sake. My ex tried with me...lord did she try. I wasn't ready then, and if this is your first exposure to heavy addiction, I encourage you to examine whether you REALLY want that in your life or not.
I could say more, but the long and short is you did what you feel was right for your own sanity and health. That's nothing to be ashamed of or feel bad about.
"Always Believe!" -The Ultimate Warrior