Im almost sure i have Bipolar disorder but from these symptoms could it be something else?

My name is Sarah
In the past 2 years i have been sooo, its hard to explain....im just not happy anymore....Im always Irritated about something....i may be sounding like a ***** but honestly im not, to look at me i would seem to be well mannered and well brought up.
-I cant sleep and when i do get to sleep i can sleep forever and wake up and feel like i slept an hour
-My grades have dropped because as much as i try i cant consentrate
-Im angry, or i have major anxiety
-Once, im done school i just come home and i feel Sooo tired, i just cant get motivation from anything....like if my parents offerd to take me on a vacation i would much rather sit at home in my room and just do something that doesnt involve moving like read.
-I could be soo happy one minute and just feel like crying the next
-My moods or so uncontrolable and i just get so upset because there affecting me at school and at work and at home.

What do i do?

And dont even think about saying "this is typical teenage behaviour, because its NOT"

Well, you're definitely describing depression. And that fact that it's been going on for two years means that you need to talk to a professional about it. I don't know that I would call it bipolar disorder as you didn't describe any manic-style moods.
Have you talked to your parents? Explain things carefully, and don't start yelling or anything like that if they don't believe you at first. The more mature you are the more likely they are to believe you.
As a short-term help, try things like breathing exercises or meditation. And, honestly, making yourself go out might help (if this makes you feel like you're having a panic attack or something, ignore me and stick to talking to your parents). But hanging out with some fun people might help lift your mood.
Don't try and just ignore this- talk to a professional and get your life back on track. Good luck!

I am not a doctor, but it may not be Bipolar disorder at all....especially since this has been going on the last 2 years. Sounds like severe depression. I would talk to a counselor or someone to get to the root of the problem.

Depression has symptoms such as crying, fatigue, mood swings, lack of motivation...etc.

You have described me when I was in High School. You need to get help. I didn't start feeling better until I actually got help and allowed myself to be on medication. Sounds like clinical depression. Don't be afraid of medication. If your brain isn't producing something it needs, you will need to do it by taking medication.
Please get help.

all answers sound good. it would also be a god idea to have a complete physical, so many things can cause so many symptoms. i have a thyroid condition which has affected every part of me mentally and physically. get checked out kiddo.

I'm the same way I will offer to talk to you on Yahoo e-mail or yahoo messenger if you want, I never have anyone to talk to about how I feel, I didn't know if you wanted to..

i am a teenager and trust me you are a typical teenager

Talk to your parents and let them know your fears and symptoms. Ask for a psychiatric evaluation.
If you don't feel you can approach them, talk with your guidance counselor at school or the school nurse. Let THEM be the ones to approach your parents; they'll have a bit more credibility with your folks.
Barring those, ask to see your family doctor and ask him/her if they think a referral to a psychiatrist is needed (and it sounds as if it is). Be sure to write everything down so you don't forget any of your symptoms.
I know how horrible it is to have bipolar disorder as a teen and not get treated. It makes one's life a living hell. Hang in there; it's worth it to get help.

Hey Sweetie,
If you EVER need someone to talk to who understands what you are going through, PLEASE dont hesitate to write me. I went through a lot of different things as a child and in result, I developed severe Post traumatic stress disorder and severe depression. I would suggest you seeing a qualified psychologist (there are many free programs for teens) and they can help diagnose and treat your condition. A lot of time just talking to someone helps. So, if you ever need me, I'm here :)