I am disagreeing with some here in that I think a diagnosis and medication could be of help - even to a 15 year old. Life was hell for me back at that age as I definitely lived with depression and anxiety. Although not diagnosed with bipolar until my early forties I can look back and definitely point to manic episodes.

To go about getting some help. Unfortunately, a youth cannot take charge of their own health decisions until 16 in most places. But there are things you can do....

Once school begins talk to a guidance counsellor. They can get things rolling along, have you see a school board psychologist, and talk to your mom. They are also trained to provide a little counselling and some support. So too can people on the other end of crisis lines. Find the number for the local mental health crisis line and perhaps a teen helpline too. Locate a mental health association for your area and get some assistance from them.

Finally, your are not alone and there are people who DO and WILL understand you.