Am I going Crazy?

Why do I have such a hard time controlling my temper? What makes me easy to trigger? I resigned my job as Chaplain at the nursing home Saturday. My boss yelled at me and I yelled back, and when she called again and said  we had to have a corrective interview, I told her I quit. I am willing to make a mistake, but I get stubborn and when an authority figure loses it, so do I. Now I am a nervous wreck. I had been deciding what to do about my growing discontent there, but I had not intended to act rashly. I didn't sleep at all Saturday night. I was up half of Friday night with aches and pains and then a patient crisis. I wonder if my constant lack of reserves is a contributary condition?