Lots of great experience shared here from recovering snoopers, lol. My profession involves investigations so it didn't take me long to perfect snooping either. Reverse directory look ups were my specialty
I've heard the expression here and in the rooms that "time takes time." I think it is safe to say that trust takes time too. You didn't loose trust overnight, just like she didn't become an addict overnight.
It sounds like you are taking many steps forward on your recovery journey. Don't be too hard on yourself...In time, as you both keep working on yourselves, things will continue to improve, no matter what the ultimate outcome.
I do understand the problem of not wanting to let your guard down for fear of being blown away again. That's a tough one. I think that is part of why the focus is on today. It may help to try to focus on the positive of today and enjoy the moments. We can not control tomorrow, and it helps me to remind myself of that each time I start to future trip.