Looking for advice regarding brain fog

Hey guys recently I quit vaping again about a week ago and haven't had nicotine in 4 days (had 2mg gum for a few days after vaping). Somehow I haven't had any cravings whatsoever which is totally different to my previous times quitting.

However my biggest issue is the brain fog. I am experiencing bad memory issues, zoning out, trouble concentrating and overall feeling stupid, similar to the feeling I experience the day after smoking weed.

At this current time I have a lot of engineering study and assignments to do for university, so if the brain fog does not go away quickly I am contemplating going back to the nicotine gum or vapes. One time after quitting for 70 days I bought a vape and instantly the next day felt like I was twice as smart. I really need to be as sharp as possible for my studies or else it makes it much more difficult or even impossible.

Have you guys got any advice or recommendations? Thanks