It is sometimes difficult to appreciate the fear induced inspiration that being around an emotionally unstable person brings. I suppose the best way to find it again is to write her as she was and may still be.
A quick list of things that come to mind:
-Cheating-Caught her passed out drunk with some guy in my bed
-Addiction-Ultra-angry drunk, possible well-hidden meth addiction
-Crying-Very upset and untrusting pretty much all the time
-Fighting-Punched me with little provocation no less than twice, picked fights with strangers
-Her hair fell out-Possibly as a result of our relationship; I was blamed anyway