Man oh man, don't know what to say except hope that you get out of this funk, just freaked out at the idea of it happening to me.
The only thing that i could relate is that it can happen that when you reach a point in your life where a thing that you used to care a lot and take a lot of time doing and for whatever reason, that thing doen't mean much anymore and you wonder why the heck did you care at the first place.
Hope that besides music you have other fields of interest that could replace this one or will take its place. If that's the case that is not that bad. But if you feel the same about a lot of other fields of interest then it could mean something more serious.
PS Sorry about your wife.