I have 2 questions, No.1 - Is it likely that I or my friend have NPD from the story behind outlined below? No.2 What's the best way to manage NPD without a therapist?
The long winded story, feel free to skim read...
A Friend I met at med school lets call her Rose, lived together and went on hospital rotations together. I felt on these rotations she took advantage of me and only drew attention to herself when it made her look good in front of Drs and patients. i.e. I would deal with "difficult" patients and doctors and she would deal with the "nice" ones. I would solely organize times and clinic venues for both of us etc
She lost a lot of weight recently, which seemed to make her more confident but then that same yr also needed emergency surgery for a cyst, her family lived far away so I was the only person who helped her out and visited her in hospital.
In the last yr of friendship before I stopped talking to her, her behavior towards me totally changed she started to compete with me about looks, boys and even how well our brothers' were doing at school lol. It got to the point where I would just avoid those topics. She also started to dress inappropriately to hospital rotations to the point where a Dr asked her who she was going on a date with later - I swear to God I didn't laugh then

She also started talking to me rudely and snapping, when I wouldn't agree with her on pointless things. I'm a stickler for speaking to people how you would like to be spoken to yourself, so I basically gave her silent treatment for a while till she apologized. It was at this point I lost a lot of my respect for her and started to distance myself.
It seemed to me she had become more insecure after her weight loss and surgery as she wasn't getting the things she expected and somehow blamed me for it.
The real kick in the guts was when she started to arrange get togethers in OUR flat with people who were my friends and hers and in some cases she met them through me. They would ask why i didn't come, like I was being anti-social and avoiding them. The most awkward situation was when I didn't tell her what day I was moving out so she arranged a dinner at our flat with some very good friends of mine, when I walked in to get my stuff they thought I knew about it and asked why I wasn't staying and I told them Rose hadn't told me about the dinner, she gave me the nastiest look that day - that was the last time we spoke properly.
What I don't understand is how Rose went from being a very close friend to an enemy almost. Was it my behaviour? Was I being narcissistic in assuming that she would always be the same and support me?
We were very close friends, and its the first friend or person that I've had a proper falling out with and it was hurtful as from my opinion we were very close friends.
I've met her a few times briefly since then and she goes out of her way to tell me how many people she meets up with and who she speaks to a lot - i really want to say to her, where were these people when you were in hospital? And I have a feeling she exaggerates her friendship with some of these people, as 2 guys she mentioned she's only known them for like 3 months as I introduced her to one of them but calls them "close friends" When I see her now I get a horrible feeling in the pit of my stomach, I can't explain it like anxiety and anger mixed together...
What do you guys think is the best course of action? Keeping in mind that I have to meet with this person occasionally as we share social circles.
If you made it to here thank you for taking the time to read it. I hope its in the correct section.