
If you really want to free yourself from negative thinking you must first understand how it takes hold in your life. You must get to its roots, see it as it develops. You have to catch yourself in the act, so to speak, and then you can really understand how you have created your own prison.
Anybody who works with audio understands what a feedback loop is. Speakers put out sound, a microphone picks that sound up, the sound is amplified, it goes back out the speaker, and then it's picked up by the microphone again... Within a few moments what could have been a beautiful song turns into a high-pitched squeal. Negative thought works much the same way.
I've heard many people explain to me how their negative thinking is justified, how they can't help but have negative thoughts because they have negative situations in their lives. Money problems, sickness, death, oppressive governments, wars, there's plenty of things in the world to be negative about. Negativity almost seems like wisdom, at least until you really understand how negative thinking works.
The problem is that while negative situations promote negative thinking, the reverse is also true, negative thinking creates negative situations. One feeds into the other, and vice versa. You have misery in your life, so you have miserable thoughts, yet those negative thoughts work to manifest even more misery in your life.