I had to kick my daughter out of my home...HER home, because I could no longer help her and her antics were literally driving me insane. She was 19 years old. Was it hard? YES. I did it through tears. We were both crying, but it had to be done. Fast forward to almost two years later, she is doing great! She is back living here, but she proved to me that she was ready to abide by my rules. If I hadn't done what I did, I truly believe she would be dead now and I would be in a mental hospital.
When you have had enough, you will do whatever is necessary to save yourself. You cannot save her. She has to do that on her own. You are not helping her by giving her a comfortable home to come to and ignoring her obvious problems. In fact, you are enabling her to do exactly what she is doing. Only you can decide when you have had enough.