I like this personality system called the enneagram.
Essentially, you find your type and it'll help you understand how you act in times of stress and times of success. By understanding how you act, you can recognize when you're in a low point. It also details why we sink to our low points and the steps each type needs to take to get out of it.
When I'm feeling low, it doesn't help to have my wife make a plan because I don't understand how I'm feeling. But when I use a system like the enneagram, I have a better idea of what's going on and can see why certain actions help.
It's a neat system.