Yes I am way older than you, and I've learned many lessons along the way. The most important lesson is that my body and mind are everything to me. As long as I have my health and sanity, everything else will fall into place. You are getting adequate rest and I assume you eat healthy, but you've had two major breakdowns already. Please don't ignore your mental wellbeing. Yes, money is important but not at the cost of your mental health. Eventually the high levels of cortisol and other stress factors will seep into your physical health as well. We are social beings. We need rest and recreation, and we need social interaction. Your body is giving you some powerful messages right now. Listen to them. Pace things keeping the long term in mind, because you plan on living on this planet for a long time. Body and mind are priceless things. Nothing can replace them ever. Even Steve Jobs realised it when he got sick.