I'm so sorry for your problems with your daughter. Some of her behavior is more than likely teen rebellion.
I am finishing a degree in Special Education with a emotional impairments endorsement. I haven't had time to really think about this and process it properly but before I have to leave today, two things jumped out at me. I am medicated for depression and have been for several years, runs in our family. I started on Prozac and after only 4 or 5 years, it stopped working. I was then prescribed Welbutrin. I am much happier with this medication because I feel as if my moods are more level. I can't really describe it except to say I feel closer to "normal" although I am not sure what normal really is. Is is possible that the Prozac is having other than the desired effect? Also, have you kept any notes on her acting out behavior? Examine what is going on prior to her behavior, what the behavior is and what her behavior accomplishes for her. Doing this might give you some incite in to what needs this behavior is fulfulling (or she thinks is fulfilling). I hope things get better with her soon. I would hate to see her get herself into something that she can't get out of.
Take a deep breath, thankfully, this too will pass.
Everything happens for a reason, maybe Dad needs to find that it isn't better out there, he needs to realize how good he had it here. Maybe he will find God and that is the most important thing when he finds Him he will know he is supposed to come home.
