But I would have to say that even anger has its place. Sometimes anger is completely appropriate. From my experience, it isn't anger itself that is the problem. Anger comes and goes. The problem arises when people brew anger, which comes in part from NOT expressing anger when it was appropriate and useful to do so - from not giving anger its just due.
People let anger cook and stew, turning it into a pressure cooker.
So part of letting go of anger sometimes has to do with expressing your emotions at the relevant time. Well, that's one man's opinion. That's why Dr. Stoll recommends the Relaxation Workbook. I simply bought some brainsync CDs, put on my headphones, laid down in bed and really did quite well that way. But many here don't like being encumbered by headphones.