I can relate to the shutting out to some degree. For over 20 years, I wouldn't allow myself to become friends with anyone. The instant I felt any kind of attachment, I'd shut them out, sometimes violently, and no one ever tried again. It was early enough in the "friendship" that I had no regrets and it saved me from all of the "stuff" that comes from getting close to anyone. In fact, during that time, my BPD was under pretty good control. Had a bad day, some bad moments, but it was doable most of the time. I had a severe resurgence the instant I allowed a person in and tried to "be friends". Have had issues ever since.