I would say this is a good topic for journaling. Write down the question, and as possible ideas occur to you, explore them by continuing to ask Why or What. Be curious. Don't stop to edit what you write. Whatever comes into your mind you must put on the paper even if it makes no sense, or if it makes you uncomfortable. Especially if it makes you uncomfortable.
I am the same way. I have always uses the deep seated anger and frustrations to do my workouts to the point that I don't know any other way. I always feel relieved and relaxed after in intese workout, and no longer feel in touch with my anger.