Questions: Health & Fitness

MHO will be given to the most in-depth answer. One liners will not even be liked (zero xper for you)=my only rule here

Back when i was in elementary i was able to solve puzzles all the time, often being able to rudimentarily come up with math equations that i had never known and learning games as well as reading large books in a matter of a day. Now after years of education and halfway to my degree i feel as though my potential is now blocked from the copious hours of starring at a somewhat piece of text. But i have to wonder, since i have tried to light that spark again and again if there is something else going on here. When i try to recall things, they are often gone from memory no matter how hard i study. I have been having mild headaches to the point of where i simply get used to it and the pain is gone as i have become accustomed; but is there perhaps anyone else here with this issue?
Me:
-Calm demeanor/sparratic at times (sometimes too calm)
-Above average IQ but not near mensa
-eat healthily, though not taking in as much calories as needed (2500 in total) since i am dieting
-Excercise 4-5 times a week
-Sleep 6-8 hours each night

Wondering weather this is simply due to hormones, i am turning 21 in a few days but i honestly am not well read on what could be occurring. Help