Internal dialogue is something we all have, and something that can hold us back at times. Still, what we must realize is that both voices, that which says we can and that which makes excuses, or rationalizes out, why we can not, are both us.
Here is a quick method to deal with a situation like this that may take a little time, but will likely yield some interesting results.
https://mailchi.mp/726db154e91b/welcome-to-wind-and-raven