You do not seem to be suffering from bipolar, to be honest you just seem to have a normal teenage boy pattern of behaviour.
Bi-polar is a kind of depression which has phases of mania. There are two types, one with depression and a few mania episodes and another which has rapid cycles of both depression and mania. Mixed episodes, or feeling both depressed and manic at the same time are also not uncommon in both types but more commmon in one, which I do not remember.
Depression episode: Symtoms include exhausion, under-eating, over-sleeping, feeling suicidal, apathetic, loosing interest in hobbies, inability to do anything, suicidal feelings e.t.c.
Manic episode: Symtoms include over eating, under sleeping, loosing ability to focus, lack of concentration, thoughts rush quickly through your head, everyone else seems to speak/move slowly, feelings of euphoria, paranoia, delusions, lying e.t.c. Usually when suffering the manic phase, people have no memory of what they say and do during the episode
Bipolar is usually diagnosed with depression punctuated with at least a bout of mania lasting over a week.
If you are worried, maybe you should go to a doctor, even just for piece of mind.