Learn this lesson: You are not required to give an answer to every question. My H was the author of that lesson! All he had to do was just look at me...without saying a word. Sometime he would raise one eyebrow, sometimes he would just grin, or he may have an angry look or a look I couldn't read...but say nothing. He refused to answer. How do you fight with something like that? Yes, I would get angry, but I did not "win" at being angry and I sure didn't control him. He showed me that he was in control by saying nothing. See what I mean?
Then realize something else. She has, and will continue, to turn the tables around in this R to make you feel that you have to prove that you can be trusted. Hey....it wasn't you that had the A! Women are good at doing that little game, too. She is the one that needs to prove she can be trusted. You fell into that trap. She is making it sound like a two-way street....and ordinarily it would be, but the first thing you know...she's making it appear that YOU were the bad guy....not her. She has you on your knees trying to make up with her. Trying to make her happy, apologizing, etc. It's kind of strange that she was unfaithful but she wants to get you into all this open R, trust, transparency, etc. Don't misunderstand what I'm trying to say. It's just that she'll get the spotlight off her and put it onto you.
Be your own man. Do what you want to do and don't feel that you must ask her permission. I'm not telling you to be disrespectful in any way but I'm trying to get you out of this mind-set you're in.
Hopefully, you will have many years of M with this young woman. However, you need to break some of these patterns that she's setting. Why does she fight with you after a trip? Why is there a big blow-up every six months? Stop the pattern.
"What is best for my kids is best for me"
Persevere = happily being patient over a long period of time