Hi X3,
Knowing what options you have in your situation (being under 18 and having your mother not understanding your troubles) is not somethiing I can help you with, but hopefully some others here can. I can help by being a listener and sharing what I've been through. Depression can hit at just about any age - in my case, I first had it when I was a teenager. Took a long time before it was clinically diagnosed though, mainly because it was passed off as moodiness and the like.
Hang with it here, and let's see where things lead.
Scythia