Perhaps take a walk and look around you. While you're doing that think a little deeper. What kinds of interests come to mind? What are some things you enjoyed doing before your daughter's addiction took over your life? What are some things you wanted to do but never had the time?
Start with small things like reading, cooking, handicrafts or photography. Not nessisarily those things but whatever seems remotely interesting. You live in a beautiful place there must be lots to choose from. Just take time out each day (an hour to start is fine) to devote to yourself and your newfound interest.
During that hour make a promise to yourself that you will not worry, obsess or think about your daughter or her situation. You will not feel guilty either. Tell yourself this is your time only.
This might be hard to do at first but as time goes on you will get better at controlling your thoughts. You will hopefully build more interest in what you are doing. If not, and you find your mind reverting back to your daughter, you might need to try a different type of hobby.
This is just a suggestion that seemed to work for me. So I thought I'd share it with you. I know it's really hard to focus on yourself when you are probably programmed from years and years of worrying about your daughter, but please give it a try. I'm a Mom too. Even though my kids are not addicts, (I do worry about the potential of my 30 year old becoming an alcoholic, she does take drinking to a higher level) we Moms get so used to living, doing and caring for them that we tend to loose ourselves and our own interests.
Good luck! Wishing you the best!