Brighthope;
You're in a depressed state of mind, with good cause. You're under much stress.
What are you doing t help yourself during this stressful period?
Have you gone to alanon meetings? Have you posted in teh friends and family of alcoholics forum above? You will find much helpful support there and wisdom.
As for your daughter, you cannot get her help unless she is an immediate danger to herself or others. Your best bet is to focus on yourself. Stop enabling her by giving her the food and necessities she needs. As long as you do that, she doesn't have to deal with any of the consequences of her actions. And you are bearing the burden of them. I know it's difficult; my son is an addict and I've turned him away many times. But, it's for their benefit. They are adults and are making choices. Allow her the dignity of living with them.
In the meantime, get yourself the support you deserve. An alanon meeting would do you wonders. And the book, Codependent No More, by Melony Beatie.
I wish you luck on your journey.
Shalom!