Emptyglass, I am so sorry for what I know you are going through but I am glad you have found this site and the support of all the wonderful people here. You have already been given some sound advice and I want to reiterate that self care is your most important goal right now. You are in for a long, unpredictable and painful journey, through no fault of your own and you will need to remind yourself to take extra care, and you will need to remember to give yourself all the grace and kindness you have.
One of the hardest parts of my betrayal was the negative self talk that was dredged up, and the inner critic who kept calling me a fool for not knowing what was happening right under my nose. It is crucial to understand that it is not a flaw to be an honest, loving and trusting person and it is pointless to try and understand what you did to cause this, because you did not cause your WH to do any of this. He chose to live a lie and make you an unknowing victim in his deception. Everything about this is surreal and unsettling, and I am so sorry that there is no workaround for that.
I am in the subgroup of betrayal that is very long term, and I'm sorry you are as well. I don't know how to help you with the mind bending looking back, trying to understand what you missed or what was real. All I can tell you is that it helped me a lot to reframe those thoughts to understand that I lived an honest and authentic life, and I can manage to look back at those years and memories through that lens without so much pain.
We were together since college too. The best of friends. A practical island, us against the world, soulmates, no secrets, all the same dreams and goals. At least that is the story he told me, until he decided he deserved more, that I "wasn't getting it done" being too focused on raising the kids than keeping him happy. The conversations where he voiced concerns were few and far between, and usually after too many drinks, always downplaying it in the morning. I thought we were good because he told me we were. I believed he was faithful because when I suspected years ago, he assured me there was no one else, that I was the only one for him. My life became about us, not me, I identified 100% as wife and mother, and was happy with that choice and that life. I was in a great place and at my most happy and accepting when I made my first discovery. I fell far and hard.
My WH did not end the affair when I discovered evidence, he pretended it was years ago and long over, because she was stupid and he felt guilty and fell back in love with me. It took almost a year to find more emails signed with kisses between them. It took one email to her to threaten to blow her life to pieces to end it. I have not yet reconciled how he kept sleeping with us both after I found out, while lying it was over for years and he adored me and wanted to grow old with me. He swears all that is true, but can't explain or even understand why he would not stop seeing her, even under threat of divorce. He just kept lying and manipulating me and telling himself that when both he and the OBS retired and moved away that the A would end organically. He probably resents that I ended it for him and can't see how horrifying it is for me to know that he willingly defied my conditions to stay married so he could keep seeing his needy, horny girlfriend. I still occasionally gag on the disrespect of the last year of their A. I could have lived with the reality of an affair, but the lies and continued inability to choose me and us over them have done permanent damage I'm still trying to navigate.
I am almost five years out, still trying to find a way to live in this version of reconciliation, in this twilight zone version of my life as I knew it. It has gotten easier in terms of how often I fall apart and how obsessively my brain keeps trying to make sense of all this nonsense. I have thought often of leaving, have come close to filing for separation, but the sticky wicket is that I love him still. He is the love of my life and the first person I want to talk to about my life. He is the last person to want to talk about what he has done, why he did it, what it means or how to move forward without pretending it did not actually happen. I did not win the remorseful spouse lottery. I have to keep reminding myself that based on the facts, he is someone I barely know, though he swears he never changed and always loved me and always will. None of this makes sense to me. I have made my safety my first concern, and it takes a while to get the lizard brain to stand down from fight, flight or freeze to work through the steps needed for emotional safety inside a broken relationship. I am still learning.
I try not to think to far ahead anymore, and just try to get through the day to day without drinking too much alcohol to numb my pain. For the record, alcohol and self medication have not been helpful in the long term. In the short term, some meds from my doctor to help with the panic attacks and the sleep deprivation were useful.
So. Hang in there. Love yourself really hard. Reach out to friends, family or support groups like us. The out of body part will fade, especially if you focus on physical things like nature walks, yoga, pursuing hobbies or interests. Take your time figuring out what this means for you and what you need or want moving forward. Understand that there is no shortcut to getting better or healing, and that professional help can be a blessing if you find the right therapist. Know that you will be on a circular and repeating rollercoaster of emotions, and should you try to stay with your WH, that needing help from the one who hurt you is tricky and confusing. Learning to believe in them or in love again is very hard.
I wish I had better advice for you, and I'm sorry I don't. There is a thread in I Can Relate for Long Term Affairs. You may find some words of wisdom there, and you will surely find your new tribe in this strange unwelcome reality you find yourself in. There are lots of books and resources online that can help, and I found Dr. Stosny's Living and Loving after Betrayal to be my most useful resource yet, but there are dozens of them out there. Find what works for you, or what speaks to you. Remember that you will get a wide variety of feedback here, most all of it helpful and kind. There may be the occasional response that stings, so remember that everyone responds based on the story they have lived, so take the advice that you need and leave the rest.
Hugs to you and please take care of yourself, relearn who you are and what you want without the filter of wife or partner and start to rebuild a life you want with the respect you deserve. Let us know if we can help, or just use this site to think out loud or to vent. I wish you a soft place to land.