Can a person with ADD control violent outbursts?

I've been with my partner for 2 years. We have been planning a wedding for about 6 months.  She is a very caring, loving and funny person.  But she gets so unpredictable and unreliable that i get nervous about her stability with work.  She has had more jobs in the two years I've been with her than I've had my entire life.  She has been upfront with me and has told me that she has ADHD, Depression and PTSD. But to tell you the truth i didn't know what that ment.  As quickly as she can be happy and romantic, she can turn and be the most evil mouthed intimidating person you could ever meet. But after she blows up, its my fault.  No matter what it was about.  Everything gets turned on  me.  I'm sure i could be more supportive, but i cant handle being the only grown-up in the relationship. She's compulsive, and if we argue, she will make me feel bad.  Today however, things got the worst it has ever been.  I broke up with her a few months ago, and would not come home until she agreed to get therapy and medication.  She made the appts and agreed. very apologetic and sincere.  I noticed today that she hasn't been taking her medications and has canceled her therapy appts (the one where they were going to see what other meds she needed).  I brought it  up to her and we got into a verbal fight.  It ended with her being physically violent.  but once she calmed down, she swore up and down that she didn't mean to hurt me and asked me if i was "over it". Again, she was acting like it was my fault. any suggestions? i don't know what to do.