I don't draw the same conclusions about your experiences, but then we are all different separate people.

I hope you can go back even though you have fears about it. The scenario you paint is created by your thoughts and fears. You won't know how it goes until you do go back.

You went to the pdoc for the pdoc's expertise and that is what she did; she advised you the way she feels is most helpful. She didn't do what your roommate said she would do or what you thought she should do; she did what she thought would be most helpful.

You note that you are not skilled at assertiveness. This might be something that DBT could help you develop so you can feel free to voice your opinions, your expectations, your disappointments while understanding that they are just that and not demands. It feels good to feel capable of being assertive. I am not often, but when I am it feels good.

Could you go back and let them know that the pdoc appointment didn't go the way you expected and see how that goes?