I am new to this forum as well but not new to the world of bipolar disorder. I have 2 kids that have bpd. You did not whine or rant. Venting is often helpful. I often feel like I must have done something terrible in my life to have 2 of my children afflicted with bpd. I don't remember signing up for this! Rationally, I know this is silly but emotionally some days are so bad that you feel like you got a raw dead. You did but it can be managed. Being 16 can be difficult all by itself but dealing with bpd adds a whole new dimension of difficulty. Keep in mind that you are not alone, stability can be achieved, and there is help out there. You are courageous, strong, and capable. I know this because you are reaching out and talking about your disorder.
Have you spoken with your doctor about your manic episodes? It does not sound like they are well controlled. Sometimes another medication needs to be added to achieve stability. You really should report these symptoms to your doctor. You don't have to live in this misery. There are many different meds out there for bpd. There are many meds that are used as mood stabalizers. Talk to your parents and ask to go to the doctor. Some doctors will even take a phone call or email and then get the patient in to see them.
One more thing. Cognitive behavioral therapy is supposed to help people with bpd. You may want to talk to your parents about this if you aren't already getting therapy. It is supposed to give you strategies to cope with some of the behaviors associated with the mood disorder. Perhaps it can help.
Stay strong and be proud of who you are! You are wonderful being you!