It's not talked about much these days but I think some ideas about the sense of self that psychoanalysts wrote about 25 or more years ago bear looking into again.

The idea that I'm just a bunch of behaviors and mental processes just doesn't sound right to me, about my self anyway. Who are you, to you? And if you aren't sure, it makes sense to me that you might be kind of self-absorbed until you do know. The loss of your musical abilities could affect that, it seems to me.

Wondering about yourself and being concerned about things that are bothering you, especially when you have a diagnosed mental illness, does not sound all unrealistic to me.

From what you have written, I wonder about your counselor, too. Maybe he's not helping. Have you considered posting in the psychotherapy forum?