This is a common feature of the human brain, it is a question answering machine. Pretty much no matter what question you ask your brain, it will search for an answer, even if the question is a non-productive question.
You brain will work just as hard to answer the question "Why am I so smart?" as it will to answer the question "Why am I so dumb?". Try taking control of your mind and asking it empowering, positive questions that improve your life.
Once you have decided what goal you want, start asking positive questions that will help you achieve this goal. You may have to experiment with what type and quantity of questions work best for you. Some people, may be able to ask one quality question to achieve their goal and others may need to ask many different questions.
The one thing that I think is consistent is that whether you choose one question or try many different questions, it is important to repeat the question(s) on a regular basis, 3-5 days per week at a minimum, just like if you wanted to work out your body.
What type of questions should you ask? I would suggest trying the "Five W's" (and one H) technique as a way to come up with questions you can ask yourself. For example:
Future reality questions
Who helped me ...?
What did I do to ...?
When did I ...?
Where did I ...?
Why am I ...?
How did I ...?
Present achievement questions
Who can help me ...?
What can I do to ...?
When can I ...?
Where can I ...?
Why will I ...?
How can I ...?
I do agree that "Why" questions are powerful, and also think that other questions can be helpful.
My advice is to pick a number of questions that you can stick with for at least one month, asking them 3-5 times a day each week. After one month, see how those questions are working for you. If some of them are working keep them, if others aren't working them come up with some other questions and ask yourself those.
I remember, I used to ask myself, "How can I feel the same way about healthy food, that I do about junk food?" Amazingly enough, it worked. In the past, when I would reach for a candy bar, I will now grab some fruit. I don't feel that I'm denying myself or having to resist the candy bar, instead, I truly feel towards the fruit, the same way I used to feel about the candy bar.
What type of questions work for you?