I can relate to some of this. I came on here becasue for the past year my counselor has been telling me I have a shaky sense of self so I was curious to know wth he was talking about. I was diagnosed with PTSD and BPD. I don't feel like I have bene myself for years. The strange part is now I get glimpses of me, for a day or so, I can be myself and have no fears of judgement or getting hurt or critisized for my opinions is hard for me to overcome.
It is crazy that is like an automatic response when I start to feel good, I feel guilty for feeling this way. My step use to everyday beat me down when i came home from school psychologically. I learned even to stay away from home, so, once I was an adult I had to keep reminding myself this was my home and I was free from that wrath! I would come home from school happy and my step dad(mr negativity) would do everything in his power to pick on me, pick verbal fights, and basically bring me down. I think with BPD and PTSD it is important to reexpose yourself to the situation and know that now it is ok as an adult. It is the most hopeless feeling having parents who you don't feel want you and come out and say that then be able to do nothign as a minor.
I think I have a solid sense of who I am now at 26 or getting there but when conflict arises in a conversation or I feel threatened it is like i clam back up and into my shell. I have many cloaks and a few years ago I thought to myself, if someone doesn't like me for who I am then I probably don't need them in my life. Since getting away from these people who are like my step dad as an adult I can function a lot better and freeze a lot less.