First of all, 8 weeks is a drop in the bucket when the betrayal means rethinking 25+ years. For me, it was 27 years of marriage and 30 years together. I am at 10 months from DDay now. Like you, I did not reveal what was going on to my kids or to the extended family. To date, 3 people know (other than the people on SI).
Recognize that the choice do to do this has a cost, but for some of us, it is worth the price.
I can say, 10 months later, I am glad I gave myself and my spouse the time and space.
But for those first months? I was one part obsessed super-sleuth; I have a reconstructed 3-year timeline from mining every text, credit card receipt, and text message (he kept handwritten copies of their texts as mementos). The other part of me vacillated from numbness to debilitating grief. Yet I also masked it all so that no one around me really knew what I was going through—another layer to the trauma.
You will find your way through, and you will have to find the right path for you.
For me, here is what helped:
1) time, and a lot of journaling. I have a secret journal where I can say whatever I want. That helps. I review it, remove the pages that, after reflection, do not feel true. I keep the ones that are, no matter how painful they might be.
2) affirmations. For me, my mantra has been this: I am a rock, and these feelings are a wave. They will wash over me, and when the storm passes, I will remain. I am the rock, and I am not my emotions, nor am I other people's emotions. I am stronger than anyone around me knows.
3) brutal honesty. I insisted that any future we had depended on his ability to demonstrate transparency and truth. It means a willingness to hear things I do not want to hear, but also his willingness to speak the things he was afraid to say.
4) Recover first, then reconcile or separate. I insisted that he understood that we both needed to recover before we could decide what this meant for our marriage. We mutually chose reconciliation, but only when we both felt recovered enough to trust that choice.
And 10 months later? It still hurts sometimes. It is hurting tonight. I still wonder if I am just too broken some days. But... and here is the important thing... there are other days that I feel like I am moving on. There are days that I feel excited about the better, more honest marriage we are building. Every day, I am learning to understand that trusting again after a betrayal is the most courageous thing we can ask of ourselves. You will learn to trust yourself again, and that is the key. That is the thing that was violated and the thing you will reclaim in time.
Hang in there. This hurts. This is hard. This forum is full of people on the same journey, and we are here for you.