Dealing with intense negative emotions
Use the body scan emotional release technique.

Be calmly aware.

Don't desire to get rid of it.

Don't try to put it into thoughts (don't try to understand whatever situation this problem arose from). If your mind continues to try to figure it out, just notice that too. Realize that you are NOT your thoughts or emotions. You are the Mastermind, the Overseer, the Watcher. You are Him that sees all!

Just be with your pain and notice how it ever so slightly changes from one place to another, from one color to another, from one feeling to another.

JUST FEEL.

Don't force anything to happen, just FEEL what is.

Eventually, the energies will dissipate on their own and transform themselves into their positive counterparts.

These instructions are ample and I can confidently overcome leftover emotions from rejection, remaining hatred after argument, and even tiredness by using this practice. All these instructions are one step: totally accepting, almost-curious awareness. If it helps, you can prepare yourself by labelling the emotions or freely writing/journalling about them until you are ready to give them up--sometimes with extremely powerful emotions you HAVE to do that as preparation.

Also, don't be so ready to give them up. There is much to learn from great suffering.

Also, this practice is definitely a Buddhist practice of the highest standard (Vipassana) with infinite room to grow and you will be doing The Most Important Thing, carrying on your cultivation throughout your life and even beyond death.