It's not surprising that we confuse ourselves with our thoughts. In a world that originated the phrase, "You are what you eat", it follows that to be your thoughts might be an improvement. You're not, you know, what you eat. That is to say you are not your body. Likewise, you are not what you think, that is the mind.
The most accurate indicator of what you are is not what but rather, That you think. After That, the thinking is almost, no, actually is inconsequential. Having this awareness you can turn your attention to the power of being lucid and free your attention from dissecting the story of thoughts the mind assembles to explain away its ignorance of the Truth That is you.
If you were thoughts, you would cease to exist in the space between the thoughts, just as a lamp does not include the space between it and the sofa. Even if your mind runs constantly, there is nonetheless space between the thoughts.
That you do not cease to exist in the space between the thoughts is indicative that you are actually this space in which thoughts may arise. As such, thoughts are entertained like guests, but you are not limited to or by their quality unless that is a thought you choose to entertain.
If you do choose to entertain the thought that you are what you think, that will be your experience until you choose otherwise either by getting to the core of how it works, or via an elaborate arrangement of thoughts that produce some other effect for awhile. Getting down to the "core" is trimming away excess thought. Sometimes you may find yourself trimming away at the idea that you are your thoughts. Other times you may find yourself thinking that things would be different if you just changed your thoughts, (i.e. from bad to good) but this strategy just reroutes your thoughts.
The hint given earlier that you are not your thoughts but the ability to think, aka consciousness, is a great place to turn your thoughts. Rather than just exchanging them for new, equally limiting thoughts even if they do seem nicer, simply notice that you are thinking and leave it at that. There is no need for adjustments or changes.
You are not the thoughts or the thinker, but the pure, unconditional stuff in which such ideas and notions are born, take root, act up, change, shift, and disappear. When you don't identify and evaluate yourself by the quality of thoughts (yours and other people's), you are free from the burden of managing them. Just let them be, and be amused, served by, done with, and independent of them. Be lucid.