I'm 45 and a lot of what you say resonates with me. I'm divorced and haven't remarried. Some days I just want to stay in bed. Used to be I'd get up earlier on the weekends to go huntin', fishin' or to play with my hobbies. Now the weekends are just another workday-either catching up on my in-town job, or chores here on the farm.
Best I can say is to talk it out and don't let it fester. I hope your wife is understanding enough to hear you out. As for me, my hound dog listens some of the time, but mostly just wants me to throw the ball again.