You definitely need to go for a full check up (with blood drawn) by a doctor. It could be any number of deficiencies, most likely your iron levels are off, or you're just not eating enough of the right things. At your age you shouldn't be so tired. Please go get checked out. If you're tired (pardon the pun) of feeling this way, then do something. It could be something as simple as taking an iron pill every day. I went on a course of iron pills and it changed my life. I went from zombie to feeling 'normal'. That reminds me, I need to get more of those glorious bastards. I don't eat red meat at all, I just don't like the taste. Also, I spend all day indoors with the curtains drawn, so I'm not getting any vitamin D from the sun. Seasonal Affective Disorder or SAD (apt) is a real thing. Google it and you'll be suprised.

I've been eating a lot of apples and cucumber, (intensely hot tropical climate and it's the summer here) and no wonder I feel like crap. Thanks, you just reminded me to take a hard look at my habits and start doing better. In the morning I'm going to sit outside in the sun for a bit too. You do the same. Thanks friend!