How can an executive stay positive as a manager when so many things are going wrong?

Try to focus on the big picture, and look to the long term trends in your career rather than the day to day cycles.
By keeping your focus on the steady progression to long term goals, the short term loses and setbacks become less intense. Remember that you alone determine what significance you place on any event (uplifting or devastating).
Also remember every day above ground is a great day!