If you need to “let go” of a feeling or an unwanted thought, try visualizing it. What works often enough for me is taking a thought or feeling, and imagining putting it on a raft that’s floating on a river and watching, in my mind, the river take the raft away. If the raft comes back, so be it. But it usually doesn’t.
I took a class in dehypnotherapy a long time ago, and there was a meditation exercise where the class leader told us to think about someone who hurt you as a kid. My father, who drank a lot, was who I thought of. Now respond to what they did to hurt you as part of the meditation.
So while I was breathing I visualized this -- I took a plate of spaghetti and mushed it around on his face. Then I put him in the tiny basement bathroom we had in our house, closed the door and said "now I want you to think about this young man!" That's when the fantasy ended.
By the end of the workshop we would address the hurtful adult as an adult would -- "I love David very much," I would say to my father, "and I want you to be nice to him."
The point being first find your inner adult and eventually respond like a responsible loving adult that my father should have been.
Once I learned that technique, I don't have much trouble with letting bad behavior stop me from being true to myself.
That works with a lot of Buddhist teachings (from lojong, to tonglen to “feeding the demons’) and the psychotherapeutic modes in shadow work, gestalt, “changing chairs”). There is something very powerful about giving the “demons” what they want, or facing them and giving the younger version the adult presence. I always marvel how a small bit of technique can upgrade a mind so it’s hard to act in (never really be bothered again by) the old ways.