Do you see a theropist at all?
I know wat u mean about not being able to take authority, I also cant. I think I know better than doctors, techers, and my theropist.
Ur 15, so really just could be out for attention and may not have a mental disorder. I know when I was 15, I just mucked up in school and was the class clown just to get some attention.
Your only young, so let your school get you checked out just in case. Because if you do have a mental illness than its better to act on it now.

Having a mental disorder is not the end of the world. But not getting along with your friends, peers, and authority figures can seem like the end of the world. If for no other reason than peace of mind, you should be evaluated to see if and what you problem may be. Bi-polar is a chemical imbalance that can be sometimes very easily solved. If you do get a diagnoses of bi-polar it is important to find a good doctor that is willing to try new drugs like lamictal, which is a seizure medication, that has far fewer side effect than meds like lithium, which can be very sedating.

Most of all, I think it is very important to speak with a therapist. Sometimes we need someone to listen to us who has nothing to lose or gain from listening to us and being on our side. If your counselor at school is too busy for this maybe they can point you in the direction of some free programs that should be offered to someone of school age.

Also, i'm not affiliated with any relious organization myself, but most churches and synagoges offer counseling to their members.

Best of luck
mia