I've managed to go from thoroughly burned out to functioning again without quitting my job. But it always feels like I'm teetering on the edge of burning out ag

I've managed to go from thoroughly burned out to functioning again without quitting my job. But it always feels like I'm teetering on the edge of burning out again. Previously I had burned out and did a career switch which helped for a while. I don't know how much useful advice I can offer but I think my own problem is lack of self discipline. I end up working when I should not be. Whenever I can muster the self-discipline to stick to a proper schedule things seem to get better.