My therapist told me that this [which I also experienced] is a normal response to trauma and shock. We have a kind of PTSD to work through.
You had a terrible shock - the bomb, which almost all of us here have had, usually comes out of a clear blue sky. OK looking back we might see signs, with the benefit of hindsight. But we were living in the belief that our relationsihp was secure. And then our life is turned upside down, our spouse usually turns and blames us, and life gets very very nasty for a while.
As the dust gradually settles we are still shell shocked. You need specialist therapy, imo, to deal with this. It is normal but hard to work through on your own.
Keep your expectations of yourself low. Expect good days and bad days. Try and find 6 good things at the end of each day that have happened. It is a good exercise anway. it can be as simple as having a really good cup of coffee, or the sun shining. All I can say is that I have been there, and thought I would be there for ever, and now I am not.
For me the biggest problem was that my husband turned overnight, into someone neither I nor my children recognised any more. I cannot talk to him, touch him or even see him. He is totally gone. In some ways it is worse than Alzheimer's which my dad died of, The person they were has toally gone, and you cannot explain it to another living soul. Only the people here know what we are even talking about - that and the therapist.
The feeling of unreality is hardly surprising in the circumstances. We are dealing with someone who insists that their altered reality is the way the world really is, and nothing makes sense anymore.