I saw this on ehealthmd.com. It was under “Living After a Heart Attack” 

Although better treatment and earlier rehabilitation programs help people recover swifter from a heart attack, adjusting to the psychological impact can take longer. Many survivors of a heart attack experience feelings of helplessness and depression.

The survivor and his or her family need to confront potential underlying fears and anxieties. Don’t keep feelings bottled up inside. He or she should be encouraged to:

• Be patient. Feelings of fear, anxiety, depression, or anger are common after a heart attack and usually are temporary.
• Discuss feelings with his or her medical team, family, and friends.
• Keep a journal. Often, writing about feelings can help a heart attack victim feel better.
• Arrange for counseling if depression, anger, or withdrawal persists for more than four weeks. Their doctor can be helpful in arranging this.

I’m glad it’s normal. I was beginning to worry.