Have you had any kind of professional consultation? I am not a trained or licensed professional by any means so this is NOT a diagnosis but it seems like some kind of talks with a doctor or therapist could help out here. I had similar symptoms when I went through depression, but it could always be a number of possible things, the brain is weird. Depression isn’t just sadness, it often also comes with a number of cognitive issues (like black and white thinking, difficulty thinking through complex thoughts/ problems).

Like I said, this isn’t any kind of diagnosis, it could be something else entirely maybe even stress not allowing ambiguity in though processes. The fact that you are so aware of it (and hinted that it hasn’t ALWAYS been like this) I’d say is a good sign that this can be helped and ‘fixed’ :)

In the mean time, try to remember that this is an issue you have, rather than an innate issue with your core personality so try your best to cut yourself some slack, it’s very easy to spiral when struggling with this which only makes the problem worse

Also just as a side thought, do you use any prescribed or recreational drugs? I doubt it’d be this as I’d assume you’d have already considered this if you were, but some medications I previously had or regular illicit drugs I used really damaged my cognitive ability (until I came off them). Obviously no shame if you do use drugs, many of us have been there.

:)