Lifesaver-
Good NESS, this girl needs a swift kick in the butt! Does she know that she is 23 years old? Is she aware that she is behaving like a three-year-old ("That's MINE!")? Even if she's not playing with it, she doesn't want anyone else to have it...
So glad you are extracting yourself from this unhealthy situation... I'm also from the South (SC) so I understand the chivalry that is so ingrained in so many of you young men
. But you're right, being a supportive friend to her (or what she defines as a supportive friend) is coming at the cost of your well-being and happiness.
As a psych major, I see serious codependency issues... get out while you can