SnowflakesByTheOZ
Sorry, that's another B
Might be lack of Vitamin D, have you been taking any sun?
Well I work in an office and when I get home I'm inside so I dont get much. Maybe that could be one of the problems. I'll try to get in more sun now that I got some days off

actually just get off fapping and improve you diet u should be straight
only stimulant would be green tea
your diet dont sound bad at all, am assuming you are in your 20s and relatively active? i would go and check it out if the tiredness impedes getting through the day. it could be a lack of iron deficiency
Go to the doctor and get checked.