Most of the people I know who make $1M per year do not feel successful. They objectively know they are succeeding, but they don't feel the way they thought they would.
Their success never cured life's uncertainty. If anything, it exposed them to more of it. Rather than feel liberated by their wins, they feel as if their performance can never dip below an incredibly high threshold. They thought they would have escaped the treadmill by now, but if anything, it's simply ramping to a higher speed.
If you are in this position, you must realize that if you don't take control of your mental health, you will burn out. Your family will suffer, your career will suffer, and ultimately you will continue suffering.
But the good news is you have the resources to make the necessary investments to turn it around. You can invest in people who can reduce your stress. You can afford to put yourself in environments that recharge your battery. And you can buy at least some of your time back.
You must approach solving your life the way you would approach solving most problems. Understand your strengths, weaknesses, opportunities and threats, and then invest your resources to defeating stress before it defeats you.