WELCOME ... and Hugs of understanding to you 0376. This infidelity dance is unexpected and destabilizing. And for many of us, it is traumatic. If you have not read it already, I suggest you google-up this article:
Understanding Relationship, Sexual, and Intimate Betrayal as Trauma (PTSD)
By Robert Weiss LCSW.
Of course, we are all different and nuanced in the way we react. So, what I found useful might be unique for me. That said, here are the tools I recall as being most helpful:
1. Peer support.
This is not your long time friends or family members, but people who know what it is to walk through the dark forest of long time marriage ending with infidelity. Basically, people like those here on SI, who have experienced the rejection/replacement thing. People who understand the phrase "De Nile is not just a river", and that "D-day" does not involve bombs or war, but it is life altering, and painful. And now, perhaps most important, people who can say "I understand. I have been there. And, life is wonderful now. Again. Finally".
2.
Kindness/Compassion.
Be kind to you. Treat you well, and take care of you. And remember you are just like the rest of humanity: perfectly imperfect with stuff you could probably work on. Which, btw, does apply to our exs and their affair partner or their new spouse (which may be one and same). I anticipate full healing involves kindness and compassion for these people we loved. Even if they turned out to not be the person we thought they were.
3. Self Recognition
It may be helpful to recognize infidelity is not about the actions of your (ex)spouse, or the affair partner(s), but about what YOU want in your life, and what is ok for you. For example, I am monogamous and I expect my spouse to be monogamous. I do not want to be married to someone who wants to be with someone else.
4.
PTSD
If you are experiencing the impacts of PTSD (as I was), it is very much as Smokenfire wrote, the work of brain stuff.
Neuropsychiatrist Dr. Daniel Amen speaks, and writes about neural pathways and the ability to "Change Your Brain, Change Your Life". Harvard-trained brain scientist and stroke experiencer, Jill Bolte Taylor talks about humans being feeling creatures who think... not thinking creatures who feel. By this, she means we are wired (via limbic system) to constantly scan our environment for safety. Basically that we are animals always asking "Am I safe?" at the primitive brain level of function. If things are good our higher cortex functions operate and we think clearly, we are calm. If the answer is "NOT safe" our limbic system is programed to go into self preservation mode. We are hyper alert, or we are frozen. We are anxious. We do not sleep well. We do not eat much. We are stuck mentally. On and on this goes as we are triggered, and have this perseverated response, re-experiencing those mucky bits and pieces, trying to find some reason, some sense of what is now an extended traumatic event. If you have some of the infidelity trauma brain stuff circling in you, the following might help.
Brainstuff 5.1
Understand and Believe. Read up, and understand you do have the ability to change this painful neural response pattern resulting from your own mix of trauma.
Brainstuff 5.2
Become a scientist of self.
Notice what is happening in you. Notice what triggers you. Notice your line of thinking, and how much time you spend thinking about your ex, or his affair partners. Notice how your thinking about him makes you feel. Notice if you are arguing with the reality of the situation. I mean, it is all over now. Do you spend a lot of time thinking things should have been different? Futile waste of time this. Are you putting yourself as the victim of his infidelity? If so, would it be more accurate to say you thought you married a man who would be monogamous ... and you were wrong?
Brainstuff 5.3
Recognizing the brain response
I think Dr Jill Bolte Taylor says the limbic system causes a 90 second bio response process resulting in the cascade of the "Unsafe" feeling state. I envision this phase as getting inline to ride the quick escalator down to hell.
As soon as I recognized the pattern starting ... what I envisioned as getting inline at the escalator ... I used some mind tools to stop. The tools that are most effective for me relate to visual processing and using what I term the "seeing mind". I believe I am switching my neuropathways from one well established route (which brings me straight down to wallow in my PTSD kind of hell), to a completely different pathway. After a few weeks using this method, my trigger moments were reduced. After a few months, I felt back to near-normal.
This is the method I used whenever I recognized I was triggered:
I would immediately look at the shapes in the environment around me, and in my mind would "draw" the outline of a shape as if I was mentally giving instruction to my hand on how to move to create the outline of what I was seeing. Obviously, things with straight lines were easier and quicker. For example, I was in a store and very suddenly I had those waves of "Not Safe" flooding in, and I started to think of my ex (maybe I was thinking about him first, and then the waves came?). Very quickly I stopped, took an deep breath in, then out, and focused upon seeing the line where the ceiling meets the wall. With my eyes I followed this line to a corner ... thinking to self I am "drawing" it all on paper ... then traveled down towards the floor, then along a shelf. I "drew" the shape outlines of items on the shelf, etc. It seemed that I needed a minute or 2 of this, and then I was ok. No escalator ride down.
Another time, I was in the tub/shower, and noticed I was thinking about ex/ow/divorce/marriage. I was starting to go into that not good place. I stopped the process by simply paying attention to the tile grout lines: "two over, 4 up, 3 over" etc. Again, I usually need to stay in my seeing mind, doing visual processing work for 1 to 2 minutes to avoid that "escalator ride". Since learning this technique I have read that playing the game Tetris, or Candy Crush (likely any visual processing focused task?) can reduce PTSD symptoms.
6.
Perspective.
Even if we live to age 100, life is brief. Between now and our individual exit date, may we all know our infidelity experiences as one of "spices" on the varied and fabulous pizza of life.