Can't stay awake at all.?

I can sleep a total of eight hours and no matter where I am, I can't stay awake.

I'll be driving to school and my eyes get really heavy. I try my best to keep them open they can't. I would have to pull over to the side and take a minute to regain awakeness...

I can be taking a test, and fall asleep too.

I've tried B complex vitamins and it doesn't work. I know it's water soluble and therefore excess comes out as urine. But, I'm starting to even doubt that ANY of it is being absorbed at all.

I've also tried coffee (I know it's overrated) so, its not a big deal. But tea used to work for me and it works for a lot of people. especially with the extra thing in it that increases caffeine's effect. But, i can drink a lot and nothing can keep me awake.

I need help.

It's really starting to become a problem when I can't drive safely to school, can't take tests without passing out.. etc

Could I have narcolepsy? or just a sleeping problem?