TeenHelp - Regarding atypical depression, and how to convince my parents I need help?

Hi! I really really need some advice so I'm sorry this is so long but I appreciate your help in advance. :hug:

OK, so I've suspected I might be depressed for a while now, but I've always brushed it off. I knew about the symptoms of depression and I never felt like I met the criteria, so I ignored it and figured that maybe it was not a big deal. Recently I've learned about atypical depression, and I'm pretty sure I suffer from that. When I read the list of symptoms I was sort of blown away by how much I recognized myself in them... I annotated a list of symptoms below...

A tendency to overeat, often with subsequent weight gain -- I definitely eat a lot; eating has sort of become my default setting. I have a really fast metabolism so there hasn't been much noticeable weight gain, though.

A tendency to oversleep -- I sleep really late on weekends, sometimes until 2pm. Weekdays are different because of school, obviously, but I'd rather sleep then, too. I'm basically always tired.

There can be mood reactivity. Mood reactivity means that a person’s mood may get better or worse as a result of a specific event or environmental change. People with atypical depression may experience a deep and persistent sadness, but will experience mood reactivity much more than people with more classic forms of depression. -- I have positive spells sometimes that lift my mood for a day or two, like when I have a really good day with friends or something. I thought depression had to be really debilitating, which is why I doubted that I was "actually depressed".

A more intense reaction or increased sensitivity to rejection, which can sometimes affect social and work relationships -- This is 100% me. I'm hypercritical of my actions and appearance, and if someone so much as looks at me weird I obsess over it for the rest of the day. I take everything personally even when I know I shouldn't, and I have trouble taking constructive criticism for this reason. I have a constant and persistent feeling that pretty much everyone thinks I'm lazy, or weird, or annoying. RATIONALLY I know this isn't true, but I still feel that way and have pretty consistent anxiety because of it (but I've never really told anyone). I had no idea that this could be a symptom of depression before.

Having feelings of being weighed down or put upon in a way that makes it difficult to motivate to do things -- I do find it difficult to motivate myself to do things. Once I start tasks I can complete them with few problems, but I'm reaaaaally bad at starting tasks. Sometimes I feel like I physically can't stop procrastinating.

Some people with atypical depression will also experience some level of anxiety -- On "bad" days I'm usually anxious... see the above bullets.

The online consensus is have to persist for about 2 years for it to be considered atypical depression; I've definitely been feeling this way for 7 or 8 months, probably longer.

My question is, how do I tell my parents? My symptoms are mostly internal emotional things they wouldn't know about/notice, and I'm able to "cheer up" in the right social environments... basically, I don't *seem* depressed. I don't know how to tell them I need help without all of this seeming really, really out of the blue, you know? Furthermore, how do I ever go about it? What do I say? "Hey, I know seem okay and I could probably function without treatment, but I think I'm depressed"?

I've considered just bringing it up with my doctor at my next check-up while my parents are out of the room, but would it be bad to go behind their backs like that? And what do I say to my doctor?!

How do I go about seeking help for this non-debilitating depression?