I have a difficult time relaxing. how can i learn to calm down and forget about my boss?

Relaxing: You are not going to forget your boss. I short course of psychotherapy should be effective in providing better coping skillls.

Breathing relaxes: One of the simplest methods is to learn to do deep breathing, using your abdominal muscles. You might also want to check out www.Heartmath.Com and their emwave biofeedback program. As you bring your heart rate and breathing into coherence (alignment), you will experience relaxation & a calming of the autonomic nervous system. Stress is a major cause of disease - learning to control it is vital.