This problem has been driving me crazy. There was a slow build up where I did not have much awareness and wanted to give my co-worker the benefit of the doubt. I just can't anymore.

There is this girl that I work closely with in a team of three. The playing field used to be level, where we all helped each other out. Since the boss is overwhelmed with extra responsibilites and cannot be as attentive, he permitted her to take on some extra responsibilities to help the three of us. At first, my co-worker seemed to know her place, and we worked together great. She can be helpful. However, she is beginning to change and overstep her line. Not even just with me, as I'm not hearing from some others. She loves the ego-boost and is getting really bossy.

I have higher credentials than her and have the ability to do some things that she is unable to do. However, she completely took over, is trying to supervise me, and is asking me questions about things that she does not have the authority to supervise me on. In fact, I can technically train and supervise her formally when it comes to certain things.

She has overstepped her boundaries even more than this, but I'm trying to keep this short. I don't want to get her in trouble, but this is going to far. What should I do? I know I should go to my boss, but I also don't know if I should confront her directly.

Also, how do you deal with the built up anger??? I have been so angry, because I've worked really hard to get to where I want to be, battled Bipolar to keep my job, and I feel more micromanaged than ever before in my career than since years back when I was just starting out. I worked way too hard to have to deal with this at this point in my career.