You are trying to make sense out of a bad situation.
It will never make sense. You know the response you got was a lie. He took the picture down for a very obvious reason - you were in it.
You know it. He knows it.
Read up on the 180 and learn how to protect yourself from enduring more pain. You can only do the 180 when you are strong enough to do so. But I am telling you it does not stop an affair — no one can stop it but the cheater. BUT you don’t have to allow the cheater to have a happy home life with all its benefits either.
The 180 is you stop being his wife. No meals cooked for him. No laundry done for him. No weekend plans with you & family that include him unless absolutely necessary. No errands done for him.
Regarding the triggers. I physically shook for the first 90 days after dday1. By the time dday2 rolled around 6 months later I was a different person.
I had a wonderful therapist that helped me through the pain.
I made plans to financially protect myself (divorce was imminent as my H was kicking me to the curb).
I had a good support system around me with good friends. Family was no help and turned their backs on me (they didn’t want to be "involved").
For triggers and panic, I took 20 minute walks when I could. I also did breathing exercises to help the anxiety pass.
My H was never on social media so I did not have that problem but I stayed off it because the OW was on it all the time. She was a social media millennial whore. 😂
Start separating and detaching from the cheater. If the cheater won’t stop 🛑 cheating then YOU have to do things to protect yourself.