Depression can play a part in anger or vice versa. I would encourage you to go to counseling and see a psychiatrist for a diagnosis and the appropriate medication. Read the articles on depression and Coping with the Blues . Exercise is an important way to decrease depression. Learn to forgive.
Bitterness plays a big part in anger and rage.
When you hold on to resentments from the past, then, when someone does or says anything hurtful or disappointing, you perceive it as more hurtful or disappointing. Your perception of events is skewed. Read the article on forgiveness . Learn to forgive as Christ has forgiven you. Anger can be managed and expressed in healthy ways when God has control of your life.