I don't think that there's a thing wrong with you wanting to be involved with your son's situation. In fact, that's just plain responsible parenting. I don't believe, in fact, that your wife's reaction was all that appropriate. This isn't about trusting her or not trusting her when it comes to your son. It was about being a father who would do anything to be sure he is safe and healthy. We are mixing issues here. You REALLY need to understand your motivations before saying anything to your wife because she knows you very well. Meaning, if you questioning your wife about your son was truly for his welfare, that's great. If, however, it was about not trusting her and getting into some kind of control game, that's an issue.
You do need to put a foot down with her, though. This wasn't AT ALL about trusting her to take care of the psychologist, it was about being a good parent. And you need to show her that you want to be involved.
With that said, has she caught you recording her before??? I mean she really seems freaked out and that really bothers me. This contol issue continually comes up.
Alamo, it's time to refocus your attentions. You have got the porn thing fixed. What else? What other things do you need to work on? How are you working on them? She's not going to believe anything you say right now until you continue to prove that you've changed.
I'm so sorry for what you are going through. I know that you are in a lot of pain. I'm praying for you.