Do I have depression?

I'm in my late teenager years. For the past almost year i've been severly over tired. I can take a five hour nap and wake up still feeling as if I havent slept in a day. I went to the doctor who ran iron decificany tests on me, and returned with the results that physically I am fine. I am overweight, but I do work out, and get excersize. My home life is very stressful. I have been dealing with emotional pain for most of my life, which causes me to be sad constantly. Mostly every night I cry in the comfort of my own space, however with friend's I am very happy, and forget about all my homelife pain. I don't know If depression is causing my fatigue, but I really want to know.