botahavfaith -
Sometimes when I get weepy or upset more than usual, I find that I've over-extended myself. You have a lot going on in your house. Besides the tension between your husband and daughter, there is probably stress related to your wanting your daughter to recover - not to mention the weight of all the every-day work of living. Also, when I have people in my house who are fighting, it raises my stress level, I don't sleep well and after a while it really wears on me. So it is not surprising that it is getting to you.
I don't know what the answer is, but I am really glad your friend showed up. Those of us who try to make a difference in our addicts' lives end up carrying a heavy burden and sometimes we don't know when to put it aside long enough to re-charge ourselves.
I pray that you are able to find the right combination of assertiveness, detachment and self-care that will allow you to keep yourself strong.