I was thinking about this, and often what happens is something bad happens, unhappy memory or future event causes us to feel a certain way. We react to it. We might be nervous and say OMG to ourselves. If we don't choose the words consciously we have a negative feedback loop influencing our feelings and our behaviour. If we take command of our words we bring ourselves into "the now" we can use "i feel" statements to chain these words to our subconscious mind replacing the negative ones that get in the way. At first this may not work. Your brain may not have anything associated with these feelings or the feelings are not familiar to your brain. If for example you are anxious, take responsibility and change your mantra. You can repeat the words till they even affect behaviour :

i feel relaxed
i feel calm
i feel confident

Don't focus on the negative and choose your program, replace your mantra:

i feel in control
i feel motivated etc.