These toxic thoughts can seriously mess up our progress on days where we're doing fine. It can hinder the ways that we see the world, it can mess up our interactions with other people, and it can freeze us in our tracks -- instantly.
Negative self-talk is easier to control than you might think. Some people may need extensive therapy for it, but most people who experience these toxic thoughts, it is actually not too hard to chip away at the bad thoughts and to replace them with good ones.
During those times that you call yourself stupid, stop and correct that voice. You're not! If you make a mistake, don't criticize yourself -- and if you do (because you can't yet help it), try saying something nice or consoling to yourself. You might also try affirmations to say after these damning thoughts rear their ugly heads. Another way to handle nasty self-talk is to add the word "yet" after a sentence where it's appropriate. For example, if you're telling yourself "I can't get anything done!," add "...yet!" as a sort of punctuation to the end of the sentence. Over time, your self-esteem will improve as you shrink that little demon who's whispering inside your ear. Try it!