I really feel for you Eggid, as well as all of the others on here who have been through this hell.
I know all too well the visceral pain, confusion, loss, and anger that you are going through. Just under 4 months ago, I discovered that my H of almost 15 years had been having an online EA with a woman in another country for the previous 15 months. He is extremely remorseful and cannot really explain why he did it. He says that he doesn't recognize or like himself anymore because of what he has done.
I discovered messages on his old phone between them. It came out that they had shared porn, tales of her rampant sexual exploits and discussed pretty much every aspect of our lives in the 15 months they had been in touch. They had messaged almost every day - at work, when he was sat next to me on the sofa, he sent her photos from our holidays and texted her whilst he was next to me in our bed. I felt violated and betrayed by the one person I thought would never do anything to hurt me and our family.
I always swore that I would drop a cheater like a stone. I am a child born of an affair – my parents finally left their respective partners and became an official couple in my late teens. I know from growing up in a fractured family just how toxic infidelity and constant secrecy can be and the log-term impact it can have on all concerned.
In real terms, it hasn’t been very long for me and I’m still struggling to make sense of it all. Some days I feel moderately okay, some days I obsess about it – my feelings of inadequacy, imagining what actually went on between them, how the OW made him feel, the pain and loss of both the man I thought he was and of the future dreams I had of us together, the crippling shame of "how could this happen?" – other days it all just hits me like a hammer in the gut and I find it hard to put one foot in front of the other. It really has made me question everything, especially my own resilience and mental wellbeing.
We're still together, although in a markedly different relationship than before. Things that used to feel natural, like saying I love you, are hard for me to do. I know I do still love him but I don't feel ready to lower some walls just yet. I'm hoping that time and communicating with a more open and honest approach about how we're feeling (good and bad) will help us to build anew relationship, but it is bloody hard going.
I can't give you any answers or quick & easy fixes. I honestly wish I could but I simply don't think there are any in such situations. I just wanted to let you know that you are not alone in going through this and whatever happens in regard to your relationship going forward, you will survive it all.