I think I might have Bipolar type II

I'm going to make this short, because I'm supposed to be doing school right now.
Basically I'll go one or two weeks REALLY happy and energetic, that's just who I am. I'm fairly happy, optimistic, energetic, etc, no negative emotions. However, I find myself going through week or more periods where I'm just always angry and depressed and pessimistic and hateful. It's like, unexpectedly, the next day i'll suddenly have TONS of negative emotions, whereas I usually don't have them, and just... no positive ones. This has been happening for a few months (probably no less than six) and I'm in my early teens. I read online that this is what bipolar II is, because I was suspecting it. I'm not looking for a diagnosis, I'm asking if you think that I should go to the doctor about this if you think it might be bipolar type II. I have difficulty doing school during this and, naturally, I don't like feeling this way. (though I do like it when I'm happy and full of energy ) Thanks so much

It's possible, but there are a few things to consider before jumping to bipolar. For one, your default mood. Have you always been happy normally? If so, that might just be your normal mood rather than a deviation, which would mean that you're more likely experiencing depression and then returning to normal. Secondly, being in your early teens, it could just be the joys of puberty giving you mood swings; I don't think I was ever so emotionally unstable (at least in a particular way) as that time in my life...

It could still be bipolar, of course, and checking in with a doctor wouldn't be a bad thing, but it's going to take time to observe, especially if it just got started. Good luck!

The rest of your post could be interpreted in various ways, but this:

"It's like, unexpectedly, the next day i'll suddenly have TONS of negative emotions, whereas I usually don't have them, and just... no positive ones."

...is exactly why I went to the doctor and got the BP2 diagnosis.

If I were you I'd speak to a doctor about it -- otherwise you risk Googleitis (you read too much about an illness and discover all the symptoms in yourself soon after)

I often use tennis, weight lifting, kayaking, cooking, and meditation to even out my mind and get grounded. What kinds of things are you doing?

I tend to agree with Lexicon, in that given your age and the length of time in question what you describe doesn't exactly scream bipolar to me. But, again, as Lexicon said -- the best thing to do is go to a doctor and talk to them about it. I doubt they would diagnose you right away, but it would start the process of having them evaluate and observe you in order to reach a determination of exactly what is going on.