Great step Anchorage!
I find that just by allowing myself to really FEEL the emotion......it dissipates or lessens in intensity.
I would suggest though that next time you may want to just write the e-mail and not send it until you are done being angry. Even if you were impeccable with your word, an angry e-mail is an angry e-mail. I find that my emotions about the subject are significantly different when I'm angry vs. not angry. Just a thought.
Remember, there are almost 'grieving' stages to a break-up. It's good to feel.
