Amen. The issue is this: If you eat well, sleep right, exercise, go on dates, and your company goes kaput in 2 years, those two years aren't wasted.
If you burn every waking hour on your company, and it goes kaput in two years, what do you have to show for that time?
For me, adding exercise and learning a musical instrument to my routine have been major wins. I can have a day where everything possible goes wrong at work, and still look back and say "I got something done." It's a pattern of life that, even when things go awry, I can say that I'm closer to where I want to be now than I was yesterday.
How much value can a miserable and unproductive person deliver?
I don't want to buy a beta product from a company, only to find out that it went out of business five minutes after the founder hung himself with his belt.
Here's my advice, as someone who's been self-employed for 5 years and recently sold a startup:
Eat well, sleep right, exercise daily, go on dates. You'll be happier and more productive.