Larry, I am so sorry to hear about your loss. I suppose that would cause a depression strong enough that would cause a loss of interest in other things that you love.
I don't have any advice, but I can tell you that the same feeling has happened to me and it hasn't been the result of anything tragic, any kind of loss, etc. Sometimes, this just happens. You find yourself staring at the collection and thinking, "I have no interest in any of this. I think I'll just dump it." The only thing I've been able to do is just let it slide and stop thinking that I have to listen to music, knowing that at some point I'll be interested in the music again.