When negative or self-critical thoughts pop up, like: "I don't know what to do" or "I'm not good enough" or "I never finish what I start"... or anything else you don't want, you can choose to see it this way:
Whatever that thought is, it may or may not be true (it's difficult to tell, when you're in the middle of the emotions of it), but, either way, if it's not what you want, then you have the following option:
Think of it as a direction in which you are currently travelling, rather than a final destination. In other words, imagine you're driving a car, and you are currently heading for a ditch on the side of the road. It may be true that, right now, the ditch is what's in front of you... but, unless you want to be in the ditch, you have the option to turn your head, and then the wheel, and head in a different direction. BUT, you can't do that if you keep looking at the ditch.
"I don't know what to do" - Recognize that you currently don't know what to do, but instead of soaking in that feeling, choose to recognize that: while you're feeling that feeling (those stress chemicals are flooding your bloodstream), the part of your brain responsible for cognitive thinking is Literally not working. So, make it your top priority to do whatever it takes to get into a calm, happy, peaceful, humorous state - to bring your prefrontal cortex back online. And you will then know what to do. This means you ALWAYS know what to do, because when you don't know what to do, you do whatever it takes to feel good... and then you'll know what to do next (because your cognitive thinking will be working again! ).
"I'm not good enough" - Choose to recognize that whether or not you are good enough, that is simply a direction in which you're heading right now (like the ditch). If you would like to be "good enough", you have the option to turn your face away from "not being good enough" (the ditch), and look for ways to feel good - to bring your prefrontal cortex back online.
Then, use ESC or another method to train your brain and body to produce more "feel-good chemicals"... and then, change the "evidence" your subconscious holds (in the form of childhood memories) that is providing the proof that you're "not good enough".
"I never finish what I start" (and all other negative beliefs) - As with the points above, recognize that it's simply the direction in which you are currently heading.. and that YOU are driving! Turn away from the "ditch" and drive in the direction you WANT to go. Head towards: "If it's something I'm excited about, and believe in, I ALWAYS finish." or "I ALWAYS finish what I WANT to get done".
In other words, don't buy into something just because it feels real right now. Don't buy into the scenery along the road - redirect your focus to the destination you DO want to get to, not the variety of negative distractions along the side of the road.
Hope this helps, but let me know if you have any questions or need clarification on anything.