catch yourself – Interesting that you read it that way; I read it as an accurate (if somewhat pointed, especially after using the word “shirk” when that is not the case) description of Rav Dessler’s final level of Bitachon. If one truly believes and acts that Histadlus does nothing, and only Hashem can do anything, then that is how he should act.
So the right word many not be “trusting”.
Bitachon means not working (but learning Torah) and having absolute belief that Hashem will provide your parnassah, because your actions do nothing to help.
(I’ll delete the last three to the extent that they are Devrei Mitzva, so “Bitachon” doesn’t really apply).
In short, the more Torah you learn, the more you understand that your actions do absolutely nothing in terms of helping any situation, the better your bitachon is. Like several people said before, becoming a baal bitachon is not easy (and you have to know where you are and be extremely honest), but every step counts.