I greatly appreciate you taking the time to share your experiences and challenges with doing gamedev. You are an inspiration to others even if you may not realize it at this moment. :)
I wish you the best of good fortune in succeeding in what you wanna do. I've personally found keeping a regular schedule helps a great deal with many things including keeping good health.
A good bit of advice from Josh Strife Hayes (fantastic content creator): "Make being healthy the easiest and laziest option possible. Set things up so that doing the healthy things requires the least amount of effort." He gave an example of setting it up so that he always has vitamin bottle ready on the counter when he gets up in the morning or he won't bother to take them, etc.