The thing that you’re thinking is the obstacle to your improvement, that you need to deal with before you can start getting better: dealing with that obstacle is the improvement itself.
It can be easy to psyche one self out.
It's sorta like the Horus Heresy, the future of destruction is created in an attempt to stop the prediction of that future. You are worried about doing the thing, and that worry stops you from doing the thing because you optimize against the worry not doing the thing.
Another example is how the thought of the thing feels like doing the thing. You get rewarded for thinking about doing the thing or telling other people you are going to do the thing.