When dealing with emotions that threaten to overwhelm, especially uncomfortable ones like fear, shame, nervousness, possessiveness, or anxiety, I've found it useful to take thirty minutes or so to sit with them.
I begin by following the breath, but only in order to calm down and find a center. I let my body relax as well.
After about ten or twenty breaths, then I shift my attention to the emotion itself. Usually there are two distinct phenomena going on: first, a sensation in and around the gut, solar plexus, and chest area; and second, a related train of thought or succession of images. These two are interlinked. The more involved I get in the train of thought that obsesses on the situation producing the negative emotion, the more intense the sensations in the body.
An interesting feature of these thoughts is that they are usually one-tracked, obsessive, and not well-reasoned. Any time I feel significant emotion, positive or negative, I notice it is more difficult to have a clear, quick, well-reasoned thought process. Sometimes that's good of course, but in the current case it's not so great.
If I notice myself getting caught up in the thoughts, and then obtain a sort of third-person view of the thoughts whizzing by, then the sensations lessen. If I bring my attention to the physical sensations themselves, they lessen, and so do the thoughts.
Once I achieve this much, then it becomes easier to deal with the emotional state overall. Often this sort of thing happens to me as I am trying to go to bed, and I can't fall asleep till I deal with it. This meditation helps.
Three times in the last two weeks, it was of particular help. Two times had to do with anxieties over "public relations" having to do with organizing the Genocide Prevention Ritual. The third time was an instance of extreme lust. I had come home from an evening with friends, and a girl I'd once liked had put her hair in these luscious braided extensions. They made her look extra beautiful, and that evening I started obsessing over trying to seduce her. I had long since decided that she was not right for me, but I felt like I needed this in order to not feel lonely and pathetic. I could witness this thought process and see how it was not well-reasoned (or moral, for that matter). But once the sympathetic nervous system is stimulated and emotion starts pumping, it doesn't want to quit. Finally after doing this meditation I was able to get enough of a grip to distance myself from the obsession and fall asleep. The next morning, I felt normal again and it was like looking back at an experience of being drunk and not in one's right mind. I didn't want her anymore, nor had I wanted her before. It was just that one evening of lust, so compelling yet so far from what I really wanted.
So suffice to say this meditation has been useful. It probably works in interesting ways when dealing with positive emotions too, but as it is not usually a "problem" to feel positive emotions I have not used it as such.
If I can now tack on a little footnote related to paganism, this meditation finds an interesting correlation in the Greek concept of ate or "madness." This was a sense of being out of one's right mind, generally attributed to divine or daemonic influence. Occasionally it was positive, as in the case of Bacchic or oracular madness. But mostly it was feared, and led to ruin. In the Iliad, when Agamemnon finally apologizes to Achilles, he attributes his offense to ate. He claims it was not his fault, for the gods put it in his mind to do so:
Zeus, Fate, and the Fury stalking through the night,
they are the ones who drove that savage madness in my heart,
that day in assembly when I seized Achilles' prize--
on my own authority, true, but what could I do?
A god impels all things to their fulfillment (Fagles translation, 19.101-105
I don't think this is a way of dodging responsibility, but rather of admitting mistakes in a culturally-acceptable context. For him to plead madness is to say he will not do it again, for he would never have done it were it not for that divine influence. That's my hypothesis, anyway. E. R. Dodds gives an excellent discussion of this in his The Greeks and the Irrational.
This Greek concept of ate or madness has strikingly similar contours to the experience of lust that I mentioned above. At the time it felt compelling, but afterward like I had been out of my right mind. In Buddhist terms emotional and mental states, like all things, are anatta or not-self, and in Greek terms they can be ate, madness arising from outside the self. The two traditions are very different, but in this case they find an interesting parallel.