It is great that you have gone for your Masters – congrats! I am a retired Management Consultant; I had to stop doing client facing work because it was too exhausting, as well as I couldn’t keep up with the “thinking ahead” requirements.
I have been doing ok doing internal work, including some teaching – averaging only 15 hours a week. Would it work for you to teach part-time, taking some time to work out how many hours you can do a week on top of your other commitments?
It has been quite “make it up as you go along” for me, but after about two years now, I think that I have a routine that works – I work Tuesdays and Thursdays so that I have plenty of time to recover – as well as being home by 4 so that I can spend time with my son. As well, when I teach, I spend quite awhile planning and studying ahead of time when I can, so that I don’t lose it half way through. This is quite a different approach to the old days, but things change and you have to adapt!