Liz,
I am so glad to read you are going to look into counseling. Depression and physical illness are intimately related. Depressed mood is thought to contribute to the development and progression of some illnesses, while physical illness can in turn increase the risk of depression.
People do grief for something they love and that they are no longer able to do ~ like your singing. I went through a identity crisis when I had to take early retirement due to health problems. I was grieving for the loss of my role as an ER nurse and the loss of the friends that continued on without me when I retired.
I know where your coming from and what your going through.
Gentle Hugs and stick with us.