Yeah, my son (16) has struggled with this all his life. He has always been a very intense person - every little thing took on these humongous emotional ramifications with him. At some point, things took a worrisome, fretful, fearful, OCDish tone. His anxiety manifested itself in fear.

As he got into his mid teens, the OCD/fear dissipated and as the fear dissipated it was replaced by extreme irritation and rage - much of what you described resonates. He's not bipolar but is diag with PDD-NOS.

At the core of it, always thought that anxiety was at the root of things, both the fear and the rage.