Your mind is territory. Every thought you let in unchecked gets to redecorate.

What you repeat to yourself becomes the background you live in. A sentence heard often enough stops sounding like an opinion and starts sounding like a description of reality, whether it came from you or from a screen. None of that happens deliberately. It happens through repetition, which is why what you let run on loop matters.

Catch one line you say about yourself regularly and look at it. Ask whether you would say it to a friend in the same situation, and whether it is actually true or just familiar. You do not have to replace it with something cheerful, only with something accurate.