Bipolar Disorder Support Group
Bipolar disorder is not just a single disorder, but a category of mood disorders marked by periods of abnormally high energy and euphoria, often accompanied by bouts of clinical depression. This is the place to talk about your experience with bipolar disorder, learn from others' experiences, and find support.
Sometimes others can help us work through these things a little better.
Time crunching is not good for beepers. I checked this out by asking the U for disability accomodations. Sure enough, when I was given extra time to take an exam, and a quiet/private space to take it in, I did way better.
By law a college or university must accomodate a "mental disability". I don't know if that is true for high school students, but you can find out by asking.
Most educational establishments in the UK have someone to address this type of issue with, so that they can give practical help.
Good luck.