LPT Request: What can I do to daily improve my memory and concentration?

I'm 28, I live alone and I don't feed well. I love reading and I've been considered a smart guy but lately I feel kind of fool, I forget things, I forget the meaning of words I used to know, I'm always lazy and sleepy, and I think I should change my habits. I use to smoke weed and drink beverage drinks every weekend.

I don't request a medical tip, you might mention some sustains you use to improve your memory and concentration though, but I would rather prefer to read some goods habits you have to improve your brain's health.