If you think you are BP then you need to see a doctor, only a doctor can give you that diagnoses. You can start with your PCP or GP if you need to and get a referral, There are many things that can cause fluctuating moods and you need to have physical illness ruled out first. Going on BP medications isn't something you just do because you think you are a diagnoses it's a serious decision that requires a though examination. I once knew someone who thought she was BP and she convinced a doctor to give her BP medications. that really messed her up as she wasn't BP. So go to a doctor with an open mind and let them figure out what the problem is, if you go in telling the docs you have something they might be more inclined to think that's what you have without ruling anything else out.