My therapist gave me a metaphor which I really liked. Everyone has a bucket and life fills it with ... dirt (although she used a less-child-friendly term involving post-digestive material). Since people don't like hauling around dirt, they try to get rid of it. For some, they can use meditation or other positive thinking techniques to empty their bucket. Others use the simpler method of dumping their dirt into other people's buckets. We all know them and we've all been the recipient of flying clods of ... dirt.
I have the particularly unfortunate combination of not being good at getting rid of dirt and of not being good at preventing others from dumping theirs on me. I have improved in that I no longer believe it is my responsibility to get rid of others' dirt but the rest is still something I struggle with.
I did try for an extended period to try and stop others from dumping on me but that did not go well. Lots of drama and accusations and even more dirt-flinging. It reinforced a lesson I learned fairly early on: I can be righteous or I can be effective. If I want particular effects to happen, then I need to swallow the dirt and concentrate on my goal. Wallowing in my anger and expressing it to its targets doesn't help me reach my goal.
I'm good at ignoring dirt in the moment and keeping my focus on what needs to happen. It's been an asset to me as an employee and parent. But when the immediate crisis or situation is over, then I have to deal with the sickening after-effects of too much dirt. And it does upset me. It makes me feel used and like I've been treated as a convenient target.
I suspect there is some kind of Zen middle ground out there where I could mentally prepare myself so that I can refuse to accept the dirt but in such a way that I don't provoke more dirt-slinging. Kind of like a shield where the dirt comes flying at me but doesn't touch me. But I'm not there yet.
I have found that writing out my feelings helps. It gets the dialogue out of my head and lets me move on. Mental meditation techniques also help, like imagining the unpleasant thoughts as weeds that I'm plucking out of a garden, or sometimes, using a bulldozer to shove the garbage aside.
But either way, it's still a lot of crap ... I mean, dirt.