There are five negative emotions that tend to get the most inaction surrounding them - we sit and stew, or lay awake in bed, or fester away with them instead of, well, dealing with them.
So, what do we do?
Hit a heavy bag? Go for a walk? Have a meditation?
Absolutely.
Also, ponder these:
I'm so angry, what do I do?
Anger is just a symbol that some of our rules have been violated.
That doesn't necessarily mean those rules were right, nor that they were even logical, but, they were violated. So what do we do?
First, take responsibility. Could we have communicated those rules more effectively? Are the rules even fair? Should we change them?
Once we ask those questions, the choices get narrowed down pretty quickly. If we really couldn't have communicated the rules more effectively, and they were understood, and we know for a fact that the person still broke 'em, then the only question left is whether we're willing to change those rules, or cut that rule breaker out of our life.
I'm so afraid, what do I do?
Get prepared, and take action. Fear is just our brain telling us we don't know what'll happen next (generally because of our own perceived ineptitude) so, either we're right, or we aren't. If we've done all we can to prepare, then it's time to take action. No sense in having some sleepless nights. Just take action. That can be as simple as writing out what you are going to do in the morning, or journaling your fears out - but take some action right now.
I'm so frustrated, what do I do?
Change. Change your expectations, change your perception on the situation, change your skillset, change your beliefs, change the questions you're asking yourself, but change.
I'm so guilty, what do I do?
First, narrow down which of your standards for yourself it is that you've violated. Are those standards you still believe in? If so, figure out what actions you could take that are congruent with those standards, and go do them.
You messed up. Own it, admit to it, and increase the awesome in an identity-congruent way. You might not be able to make "the thing" better, but you can ensure it never happens again because of you.
I'm so disappointed and hurt, what do I do?
What expectations did you have that were unmet? Were those expectations reasonable? Could you have communicated your expectations better? Did the person who broke those expectations do so purposefully?
What do you really want? Do you want an apology, or do you want a promise?