This is one of "22 virus definitions" (thought-mistakes that cause ineffectiveness and unnecessary negative emotions).
The same is true of questions like, "What are they thinking about me?" or "Why aren't people buying my product?" These questions are not answerable from inside your head, so they will go round and round, upsetting you and getting you nowhere. Those two questions can only be answered by asking someone else.
"Why am I so committed to failure?" That may or may not be answerable, but I'll tell you this: You'll never know if you got the "right" answer. A much more productive thing to do with why questions of that sort are to instead ask HOW.
Be very careful with the questions you ask yourself. Questions have a powerful way of generating trains of thought, so the questions you ask make a big difference.
When you feel discouraged by a setback, keep your eye out for unanswerable questions and replace them with questions you can answer, such as, "What will I do today to move my goal forward?"
See the complete list of definitions: The 22 Virus Definitions.