I'm a teenager with something...

Hi
I'm 17 years old and I think I have something (not necessarily clinical depression) but I don't know what and I don't even know if I do or if it's just normal.
It started in November 2011, and since then every few months for a few weeks to a couple of months, I experience many of the symptoms of depression like fatigue and emptiness and hopelessness. I just don't want to get out of bed most days and interacting with people is a huge effort. Usually it feels like I'm in my own head most of the day and I'm disconnected from other people and their lives. But I'm not sure if what I have is depression because I haven't been able to find something that describes the anger I feel.
It's messing up my relations with my family members. It's like all someone has to do is TALK to me about ANYTHING, just say one word and my anger spikes up to 10. I'm aggressive and hostile, never violent but always aggressive and defensive and constantly irritated and angry at everyone (while I'm in the empty/disconnected stage, not other times). If I'm on the computer watching TV or whatever, I'm in my head and I'm not happy but I'm not angry either. Yet the second I have to interact with anyone, I'm angry about little things, and it feels almost uncontrollable- like I know it's irrational and I'm overreacting but I can't help it. I don't even care.

It's not like that with friends at school (I have about 4). With them, my mood often lifts even if I'm in an empty/meaningless phase, but a lot of the times even interaction with them is too taxing and I leave because I just can't do it anymore. They don't irritate me or make me angry though.
Other times, after the empty phase is gone, I'm absolutely fine and happy and it feels like I can do anything, be anything, whatever I want. Not mania though.
My self-esteem is also like a yo-yo. Sometimes I feel like $#%^ and it's during the empty phase and then other times I feel gorgeous and funny and absolutely amazing.
Right now I can't remember what it feels like to be happy. I know I was, I think in mid June? But I can't remember what it feels like to feel any sort of emotion except for anger.

I just wanted to ask if this feels like depression to any of you? Most of it seems like it is to me, except I'm not sure about the anger part and I've never gone to a doctor so obviously I could be completely wrong and there's nothing wrong with me at all. Also the disconnection/stuck in my head bit I'm not sure about either. Thanks