To re-iterate points I made in a couple of previous posts (Self-improvement Gurus and Phoney Self-improvement), my beef with self-improvement culture and positive thinking fascism is that much rather than aiming to prove things to yourself and others in order to be a more successful social conformist, the aim should be to fully accept yourself in both your strengths and weaknesses based on your unique individuality and however much the practice of this self-acceptance offends and goes against conventional preferences and expectations.
Largely, self-improvement ideals are based in a polarity of fear, e.g. of not fitting in or being too 'negative' about the world.
Self-acceptance ideals are by contrast based in a polarity of love, for one's Creator-given individual person and for what one is able to do that is positive.
And, as I've written before, my entire philosophy can be summarised by the maxim
"Always choose love over fear."