History doesn't usually repeat itself, but it does often rhyme as at the end of year 17 of my teaching career here in Texas I started feeling like what you described. It started feeling like burnout, even though I had a good position teaching middle school band in a nice suburban school district setting.

During year 17 I started looking at other teaching options as I knew I wanted to stay in teaching. So I started applying for positions in other countries and after 2 years I landed one in an American school in East Asia but teaching elementary school music instead of band. It turned out to be exactly what I needed, as a change of pace by literally leaving the state and the country was fabulous. I signed a 2-year contract over there and afterward I returned to Texas to teach middle school band and made it all the way to the end of 35 years of teaching successfully and I really enjoyed most of it.

My subsequent teaching positions here didn't change much, but I changed. That made all the difference. I also didn't let my jobs define me and there was always a life outside the band hall. I made sure that I had other things "to retire to". It worked well.

I highly recommend considering a drastic change of pace, location, teaching assignment, etc. as for me that worked wonders and doing something that drastic honestly gives you a new perspective on everything career-wise.

As a side note, I returned to Texas mainly because of the Texas Teacher Retirement System as I knew it was best for me to return here to finish my career in the Texas system. I've now been retired for 10 years and life's great. (I also made sure I got vested in Social Security through outside work during my career). I'm still playing music and teaching on the side now and then and retirement has been nice and generally easy.

You might consider making some sort of drastic change too, be it a different location, different position, different field, etc. I highly recommend it. I know it worked for me and I'd do it all over again if I had to.