I'm 56, and a couple of years ago I was very much where you are. I was used to hard work (about a dozen startups over the years), I was used to learning and excelling and being recognized for it. Until I wasn't. To keep a long story short, I was able to retire and took advantage of it.
I highly recommend that you take a good hard look at what it would take for you to get to retirement, and make a plan. It might require cutting back in some areas, but if you don't figure out how to do it then the universe will and it'll probably be worse. Your plan might involve "one last push" to build up savings, or it might involve a "wind down" at a less stressful kind of job that you can sustain for longer. That's up to you. One thing I will say is that I've known several people who tried the "learning new things" route as an antidote to burnout, and it backfired badly. They ended up being even more stressed, unable to perform at their accustomed level, younger colleagues being resentful, etc. Maybe it'll be different for you, but it seems to me that learning new things is best done on your own time - cutting back on work hours to make room if necessary. A sabbatical or a period of part-time work might seem like it's just dragging things out even more, but sometimes it's the right strategy if it keeps you from losing it altogether.
I highly recommend that you take a good hard look at what it would take for you to get to retirement, and make a plan. It might require cutting back in some areas, but if you don't figure out how to do it then the universe will and it'll probably be worse. Your plan might involve "one last push" to build up savings, or it might involve a "wind down" at a less stressful kind of job that you can sustain for longer. That's up to you. One thing I will say is that I've known several people who tried the "learning new things" route as an antidote to burnout, and it backfired badly. They ended up being even more stressed, unable to perform at their accustomed level, younger colleagues being resentful, etc. Maybe it'll be different for you, but it seems to me that learning new things is best done on your own time - cutting back on work hours to make room if necessary. A sabbatical or a period of part-time work might seem like it's just dragging things out even more, but sometimes it's the right strategy if it keeps you from losing it altogether.
Good luck.