It can be a hard habit to break, but it's possible to get out of that mode and into the "sell something or die" mode, where you consistently show up and take action like your life depends on it.
It all starts with changing your self-talk. For every one negative thought, consciously find five positive ones, whether it's about you, what you're doing, etc. You can do it.
There is power in the pen. Keep a journal or a notepad of your thoughts or what you're worried about and examine them later. Then write what really happened.
I used to do this...and often felt silly, so my thinking pattern shifted rather quickly.
Change crappy statements to questions - "I can't do this!" could become "How can I do this?". There's always more than one way to skin a cat. Find it. It's not about things being perfect. Just believe you can. And you will.
How are you taking next steps?