Stress is not a character flaw. It's a signal to be respected. A signal to really listen to.
It shows up when what's being asked of you is bigger than what you've built inside yourself - your systems, your habits, your preparation.
Most founders try to "manage" stress with more doctors, more meds, more time off, and more and more side quests.
The right move is to study it. And study it immediately. When something stresses you out, that's the map. Consider yourself lucky that your body is intelligent enough to give you such a strong signal to go and fix something. The answer is somewhere there. Go build what's missing there. And that takes serious work.
The entrepreneurs who last and build companies way beyond themselves aren't unshakeable by nature. They just closed enough gaps that the next wave doesn't knock them over.
So stop treating stress like the problem. It's the answer.