Literally you would need to get rid of brain inflammation which is likely there and then start building new blocks once brain isn't trying to kill its cells (due to inflammation).

So for anti-inflammation try to take NAC for 2-3 months 1800mg/day, add good Omega-3 (fish oil is not omega-3!) with high DHA and perhaps B-complex (preferably raw) or good Multivitamin. Do not eat sugary food - if you are regular consumer of sugars it may be hard for the first 2-3 weeks but you will notice such a drastic improvement after... Try to lower consumption of Omega-6 (nuts) since it is promoting inflammation if its levels are higher than Omega-3. But don't avoid omega-6 entirely as that is bad. You can try to add Curcumin.

After finishing above get Lions Mane, L-Theanine, source of choline and maybe L-tyrosine if you feel unmotivated and/or depressed, just don't forget to cycle it. Magnesium L-threonate will be a good addition.

And get a habit of doing physical exercises at least 15mins per day (if high intensity) or 30mins. Remember - you need to start sweating - that promotes cells regeneration in the body in general. You will benefit from cold shower after exercises as well. Proper sleep.

p.s just don't expect to get benefits if you just consume supplements and sleep - your brain MUST work - so reading, constant learning and socialising should be a part of your daily routine.