I caught that immediately.....the part where she was mad b/c you were late. Crazy. She's looking for things to blame you.
I hate to say it, but I think there is only one reason she would be on the computer late hours like this. May be a new OM, but I think it is a man. Don't know anything else that would cause a woman to lose that much sleep and take away from everything in life.
She is playing you for a fool b/c she doesn't think you will catch her in the act (computer activitey) or follow up on the history. (She's probably erasing history) She will act outraged at your mistrust in her, etc., but she continues to do it. She's throwing just enough cumbs out there to keep you completely off balanced and to give you just enough hope so you won't investigate her new love interest.
I tried to see the posivitive in everything, but I have to be frank and tell you that I believe she's in a strong EA. The BS she said about looking at pictures of dog? Why wasn't she spending all that time with the dog while she could? You look at pictures "after" the dog is gone.....not during the last few hours you have with him. Then she continues her computer activity late into the hours even after you call her hand on it. It's almost as if she is trying to see how far she can push you before you give up and give her walking papers.
If she was not continuing her computer late hours, then I would think her mood swings were due to her coming out of the EA.....but I don't believe she's coming out. There may have been some change in the EA R, but she's still in one. Anytime a woman "shuts" hereself off in a room......it's for privacy, and why would she want privacy from her H unless she was doing something inappropriately.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!