Tired teen, need your advise on this?

I'm a teenage girl. and randomly at different times, i feel extremely exhausted. No. i don't have mono, I'm not anemic, i don't have diabetes, and i don't have cerebral meningitis. When i drink an energy drink, it's a quick fix for about an 1-2 hours. then after that, i crash. tea. coffee. energy drinks, nothing keeps me awake for more than two hours. and yes, i drink lots of water. But even when I am well hydrated, i still am very tired. This has been going on for more than 3 months, and is getting worse since school started back up.
I have gone to the doctor, had blood tests done, and thinks I'm just going through a growth spurt. I haven't grown a single inch since 7th grade (I'm a senior now). And what growth spurt lasts 3 months, and yet i don't grow. I haven't gained weight or anything, nothing about me has changed but I'm very tired. My doctor thinks this something that will just pass, but it's been 3 months+ has anything like this happened to you, or a friend? and what happened

also, when i take naps, i wake up just as tired as before, and when i wake in the morning no matter how late i sleep in, i feel exhausted. I have tried going to bed extremely early, this also doesn't do anything.

Time to see a new doctor.
Being that tired is not normal and it concerns me that it has been going on for 3 months.
It could be any number of things going on.
Go get a 2nd opinion and push to have it invetigated.
Good luck.

you're probably just really stressed

I suspect you might be nutritionally deficient. That and you consume too much caffeine. You can reach a point where you can ingest too much caffeine, and it will actually have a negative reaction.

Try taking a good multivitamin, that will help with any nutritional deficiencies you might have.

Too much sleep just makes you sluggish. Stay away from caffeine, especially late at night, because that will keep you from sleeping as sound. If you have recently started a menstrual cycle, this may drag you down too. Try making sure you are eating healthy, alot of times this will give you a boost. Exercising will also get your metabolism going and give you more energy. Lots and lots of water will help too because sometimes the toxins in your body will drag you down. Also, try taking vitamins.

I think I know what it might be...
try looking into "gilbert's syndrome", its basically a genetic thing to do with the liver's ability to process stuff... and one of the main symptoms is chronic fatigue...

anyways, lots of people have it and it sucks... but in the end, it could be worse..