Feeling burntout,cloudy, tired, unable to concentrate, forgetful...?

im 17 years old and i guess for a few months now ive been feeling burntout... tired... no energy, unable to concentrate, forgetful... i dont do much throughout the day.. its very hard to get out of bed in the morning. i also feel cloudy, ... or like i am high or something. please anyone any help would be great. i feel like im getting alzheimers at an early age = / i went to the doctors and took a blood test... they said everything seemed okay but to stay away from fried foods. i dont even really eat fried foods.... but that didnt help at all .... im still feeling this way help!!!!!! its really affecting my life = [