Man, lucky you. I used to tell my doctors again and again that I feel tired all the time, but they never took it seriously. First they didn't believe me, then I developed depressive episodes and they blamed it on that, then I developed a caffeine addiction, and they blamed it on that. But the depression theory doesn't make sense chronologically, and the caffeine addiction is an attempt at self-medication that backfired. Even if you can convice them, that there might be something physical, they just tell you "well as long as that's your only symptom, it's nothing that threatens your health." It does, though, because I need to function! I'm pretty sure it's a major contributor to the depressive episodes.
But, yeah, if you can't tell, I've given up by now.