I wonder how old you are. I have felt this way throughout my life. It took on different ideas and meanings though depending on my life's stage. I am 50. When I was younger, the sense of loss was connected to pressure I ought to be doing something. In my 30s it seemed more to be a sense I didn't know what to do with myself. Now, at 50, I feel life has gone by and that I should have done something with myself.

My suggestion is to try and experience different things. Maybe an art class. Maybe a book club. Maybe volunteer work.