Why does commanding at this level overwhelm me?

You did not get weaker. The role got bigger, and you are still trying to carry it the old way — by controlling everything yourself. That has never worked, for anyone, at any level. Most of what feels like your job is not your job. Whether a decision turns out well after you've made it carefully. What your people say about you when you leave the room. Whether every problem gets solved today instead of tomorrow. You are exhausting yourself holding things that were never in your hands. If this weight is affecting your sleep, your health, or the people closest to you, do not carry it alone. Talk to someone you trust, or a professional. A page can sharpen your thinking. It cannot replace a person who knows you.