Quite often, water and being adequately hydrated will help your memory a lot, since you won't be as fatigued and lethargic, and it will improve blood flow to the brain. I also find that keeping a daily diary (or even just a gratitude journal) helps a lot because it activates a subconscious process that life is worth remembering. Finally, watch out for beliefs about memory. Often people think negatively without realising it, affirming things like " I'm so forgetful, I forget everything, I have a goldfish memory, I'm as thick as shit, my memory's going as I get older, " and create just that in their experience.
Supplements saved my life!! I want to share this with everyone who is in the same place that I was.
You can find several lectures on youtube where several studies related to this topic are discussed by doctors.
Make sure you are not in a low thyroid state. Or deficient in iron, Vitamin D, vitamin C, B6, B12, folate, zinc,magnesium, omega 3 fatty acids ( that you get from fish oil ) . Take a look at your diet and see if certain foods alter your mental functions or your gut health. For me it was dairy and gluten and the high sugar and deep fried foods. I consume all of these in much lower amounts.
Also there are some ayurvedic combinations containing Brahmi , Ashwagandha etc that work wonders for me.
works super well!