At first, I felt like I was talking about the A and the pain non-stop. For me, it took three or four months to go an hour without thinking about it, and affected EVERYTHING. I was so devastated, I would go to work and get nothing done. I own my own business, so I didn't have anyone who held my feet to the fire, and I struggled. I couldn't get anything done around the house, I couldn't function. It felt like everything was a lie, and my mind was working overtime. I was exhausted all the time because I couldn't sleep.
BUT the upside is it gets better. If I read your history right you are only a month or so from D-day. I am seven months now, and now I make it a few days with only flashes of, "oh yeah, my H cheated on me". I get sad, but the lows are not the debilitating low it was at first.
My H and I had to find time to talk about it not during work hours for him, because it would make him as non-functional as me.
Our MC described it like this: You have an injury and it is real and it hurts (like a huge gaping gash on your leg). You do the immediate emergency care, and stop the bleeding, but the wound takes time to heal. It doesn't immediately stop hurting. Its there and needs to be taken care of. You would bandage it and care for it so it doesn't get worse, but as much as you want it to just be done, it takes time for it to heal. There are somethings you can do that make the pain less (like talking, NC, etc.)things you have control over, but the injury is still there, and there are things that only time can heal.
For me it has been a couple months where I could step back and say, "What made this happen?" and not be on another emotional roller coaster.
Take care of yourself. Do the things that really must be done (i.e. feed the kids), but don't obsess that your blinds aren't spotless or your floors.
You won't be this way forever!