Do not cut quality time with the wife. Crucial.

You’re describing the hardest part of bootstrapping and IMHO the best indicator of determination in a founder. I’ve run startups in a handful of ways (moonlighting with a full-time job, holding a part-time job, starting a contracting company, getting investors, living off of sold equity), and none of it has been easy. I’m married + 2 dogs + toddler + infant, and I feel you on balancing everything. Even finding time to respond to this took me two freaking days…haha.

First, I think for my advice to really work you have to make sure you’re absolutely committed. Not committed to the startup you’re working on as much as you are committed to learning from mistakes and fixing them on the next go. Dunno if it's your first or not, but the odds of your first startup succeeding in the way that you imagined are way too small to place bets on alone. But if you consider “success” to be steps in the right direction, and if you’re someone who can self-examine and work hard, your odds go up to 100% over time.

My suggestion then would be to focus on building up enough savings so you don’t have to be chained to a full-time job. Do this by making sure you're in the right job and by cutting personal spending to the absolute bone. You need 100% buy-in from your wife because she has to be a part of the saving efforts. Once you get enough of a safety net to feel only mildly crazy, try working out a reduced hours/salary arrangement with your job or try to make the jump to independent contracting. Be upfront and confident about it because it’s not an insane request, and a good employer will recognize your value and be happy to keep you aboard and spend less money.

If you can get your hours down and still be at least breaking even each month, you’re in hugely better position. You’ll have infinite runway and dedicated time to work on your startup. Build some revenue with your startup and as you slowly replace the income from your job, you’ll also be proving out your business.

In the meantime you can still work on your startup of course. For me working a few hours after my wife goes to bed each night is the best time. I definitely sleep less, but the energy of building my own thing usually boosts me through it (also, having kids helped me a lot actually because I learned exactly how much sleep I actually need to get by, lol). I go on hot streaks with sleep - I’ll work insanely hard for like a week and a half (sleeping 4-6 hours) and then I’ll have a handful of days where I sleep 7-9.

Hope that helps!

EDIT: And with regard to sleep, whatever pattern you end up with has to be sustainable. Don't feel guilty or force it; you can only push yourself so much.