I think I understand your pain, I went through my first episode of Psychotic Depression when I was 15, and I kept on wondering if I was the same person as I was before. I wonder how I had forgotten the way I acted just 8 months prior. And with my current episode of Psychotic Depression, I struggle to understand if the way I'm acting now is the same way that I was acting just a few months back before I started college.
I hope you start to feel better.