Principles are ways of successfully dealing with reality to get what you want out of life.
Ray Dalio, one of the world’s most successful investors and entrepreneurs, cites principles as his key to success.
"I can't get enough sleep" is not a problem; it is a potential cause (or perhaps the result) of a problem. To clarify your thinking, try to identify the bad outcome first; e.g., "I am performing poorly in my job." Not sleeping enough may be the cause of that problem, or the cause may be something else--but in order to determine that, you need to know exactly what the problem is.