Why does alleviating certain anxious thoughts require so much slow and deliberate thinking? I suppose it takes practice...and is ultimately worth it.
Have you looked into meditation?
I should try it...sometimes thinking too much makes the anxiety worse
I too struggle with anxiety, and wish I was disciplined enough to give meditation a good go. (I'm reading How To Change Your Mind by Pollan now, so that is front and centre again.) Years of psychotherapy have helped, but, what's helped just as much, if not more, is a year on anti-depressants. I don't advocate anything outright -- I've regressed a lot in lockdown, for example -- except exploring all your options.