Sorry to hear you are going through this. Al-Anon might prove useful to you in detaching from your daughter's choices. You may wish to consider having her evaluated for an inpatient or partial/outpatient program if you suspect or know for a fact she is using illegal drugs.
If she does not go to school you can be held liable as the parent for truancy, which would involve fines and court dates for you and for her. Same thing goes for anything she may do while under the influence, for example an auto accident. It behooves you to protect yourself and your family from any collateral damage caused by her choices, while at the same time, beginning to detach with love in order to protect your own sanity.
Best of luck.
