Some really good experience and advice so far. I think the number of replies also tells you that you are not alone!
I'm not a psychologist. Even if I was I'd still have no miracle answers for you. My wife is a trained counselor though so I know it's important to recognize signs of depression. It can be an insidious thing if you don't recognize / admit you might have it. You're GP may help with this. I suppose what I'm saying is don't just label it "mid life crisis" and ignore it.
Like many I've experienced similar symptoms - mostly because of my job and sometimes because of traumatic life events. I'm not one of these lucky people who "love" their job - it's a chore that needs to be done to pay the bills and I'm
over it! It's a constant effort to not let it get me down! Definitely looking forward to retirement!!
And that's just it. The world is a beautiful place (believe it or not) - especially if you're on the right
. Whatever your circumstances or means though, look for the positives, be content with what you've achieved and have, and find something to look forward to. Also, don't put up with bad relationships - I've had a couple that I've had to expunge!!