You're expecting output from your brain, while it's been affected by the virus.
Perhaps, instead, feed some input to your brain. Spend your time reading some nice books, memorise some interesting things, learn something fun. Input brings order and clarity to the mind.
Since you have all the time, now that you can't be productive anyway, spend that time creating some order in your mind. Feed your mind with all the stuff it's been lacking.
Aside from that, I find that vitamin D, magnesium, and iron supplements help with quick mental recovery from a cold.
Perhaps, instead, feed some input to your brain. Spend your time reading some nice books, memorise some interesting things, learn something fun. Input brings order and clarity to the mind.
Since you have all the time, now that you can't be productive anyway, spend that time creating some order in your mind. Feed your mind with all the stuff it's been lacking.
Aside from that, I find that vitamin D, magnesium, and iron supplements help with quick mental recovery from a cold.