It's like I read on Serenity's thread today: you need to DB D18. Set boundaries and enforce them so she learns that there are consequences for her actions. If she wants all the rights of adulthood then she needs to accept the responsibilities as well. I know you just want to do whatever you can to spare her pain, but the best thing you can do for her is to teach her how to be an independent, responsible person. And if that takes tough love then so be it.
[Don't you just love it when non-parents give you advice on parenting? We just see things from a different perspective.]
I vote for starting with a glass of wine in the evening to see if that helps. It's heart healthy! If that doesn't help relieve the stress then definitely talk to your doctor about AD or AA meds.
Do I need to start telling stories to cheer you up? Pick your topic.
If you love somebody, set them free. http://tinyurl.com/2empx2g