Trying...a big welcome to you and some :ghug3 of these :ghug3.
1. Breathe
2. Your daughter is 18 years old. It might be time for you to tell yourself you did the best job you could for your daughter (pay no heed to what others will say) and now it is time to let her go.
3. Your home, your rules. If she doesn't want to abide by them then show her the door.
4. Get yourself a copy of Co-dependent No More by Melody Beattie. Beattie uses life with an alcoholic in order to make her point about how YOU are responsible for how you feel, that you have no control over others (and how they feel, your family included) and she explains how and why boundaries will protect you.
5. A 12-step group like AlAnon might be a good place to find support for you at this time. Check online for groups in your area and get yourself to one this week.
Sending you positive thoughts. Please let us know how it goes.
ARL