Has anyone here developed mild cognitive impairment and recovered from it after getting adequate sleep?

I was only getting 4-5 hours of sleep per night for about 2 years and now I am facing cognitive difficulties. I’ve been to a neurologist and one of the tests suggested that my working memory is impaired and that I have cognitive decline due to aging despite only being 30 years old.

Can anyone attest to whether or not improving their sleep helped them regain cognitive function?

Thank you for any and all responses.