Increasing salt intake had helped me a little

this is going to seem counterintuitive but I have found the best thing to do is let yourself sleep a little extra, and then when you do get to work do as much as you can then not be too hard on yourself. brain fog is a tricky thing just like any other condition that happens in your head. Then take your time and try to keep track of your habits by journaling or just keeping notes of what you do in a day that way when a brain fog comes you can look back and see if anything in particular seems to trigger an episode