Sometimes I feel burned out also. Then I talk to my wife, who has to work at least 8 hours every day at a very stressful job. We still have a boy in college and one in high school, so we have at least a few more years of "carrying on".
From time to time over the years, I have attempted to go back to a "real" job, and that quickly makes me appreciate being a musician!
One bit of advice--if you have time and haven't done it, go play an hour at a few nursing homes. You will quickly discover how great it is to play for a really appreciative audience. Just do the songs you normally do, they will be fine, and so will you.
DonM