Growing Zen

The enemies such as hatred and craving
Have neither arms nor legs,
And are neither courageous nor wise;
How, then, have I been used like a slave by them?

For they dwell within my mind,
At their pleasure they cause me harm;
Yet I patiently endure them without anger.
But this is an inappropriate and shameful time for patience.
(Shantideva, The Boddhisatva Way of Life, 4:28-29)

Unhappiness is a conscious, pointless choice
"If maintaining a balanced and happy state of mind even in the face of adversity is a key factor in preventing hatred from arising, we still may wonder how to achieve it. Shantideva says that when you are faced with adverse circumstances, feeling unhappy serves no purpose in overcoming the undesirable situation. It is not only futile but will, in fact, only serve to aggravate your own anxiety and bring about an uncomfortable and dissatisfied state of mind. You lose all sense of composure and happiness. Anxiety and unhappiness gradually eat away inside you and affect your sleep patterns, your appetite, and your health as well. In fact, if the initial harm you experienced was inflicted by an enemy, your mental unhappiness may even become a source of delight for that person. Therefore, it is pointless to feel unhappy and dissatisfied when faced with adverse circumstances or, for that matter, to retaliate against whomever cause you harm." (Tenzin Gyatso, the Fourtheen Dalai Lama, The Compassionate Life, 80)

Smiling at Your Anger (a gatha by Thich Nhat Hanh):
Breathing in, I know that anger makes me ugly.
Breathing out, I do not want to be contorted by anger.
Breathing in, I know I must take care of myself.
Breathing out, I know loving kindness is the only answer.

I love the timeless quality of "I know that anger makes me ugly/I do not want to be contorted by anger." The contortion happens in the moment, and the contortion happens through chronic indulgence of anger. So, anger must be managed in both the moment and in the mindset/lifestyle/thought process.

Mindfulness and embracing negative thoughts and emotions
I've had great success dealing with unpleasant and negative thoughts and emotions by observing them mindfully. To be mindful is to be aware of what is going on, to observe without pursuing or rejecting. My most effective analogy I've discovered so far is mindfulness is like sitting on a park bench, watching people walk by. Your thoughts, feelings, and emotions are those people. You sit and observe, without chasing anyone away, without chasing after anyone. This is how I practice mindfulness meditation, and this is my goal for living mindfully in the moment.
Thich Nhat Hanh (sorry, I didn't write it down so I don't have the citation, but it's in either Going Home: Jesus and Buddha as Brothers or Being Peace) gave me the key for dealing with negative thoughts and emotions: you have to be mindful about them and you have to embrace them. Not as in facing your anger and embracing by saying, "You're awesome! Come in and take over my mind and life!" But as in facing your anger and embracing by saying, "I recognize that you are here. That is fine. I recognize your presence, and I release you."
Whether you reject or pursue something, it is the same outcome. It is to have it control your mind and dictate your actions. So, if you ignore and reject your anger, the outcome is essentially the same as pursuing and indulging your anger. It is psychologically, emotionally, and spiritually damaging.
To acknowledge, mercifully embrace, and release something is to maintain your conscious thought, peace, mental stability, and personal agency. It is to nurture your mind and spirit.

It's kind of a surreal experience to mindfully acknowledge, embrace, and release negative thoughts and emotions. Every time I've been able to do it, I don't even need to consciously release them. As soon as I smile at them and embrace them, they vanish and I'm left with a steady sense of peace and wholeness. It's like they just need love to be transformed.

Come to think if it, isn't that true of everything?