When you had your first separation (14 months) did you keep hope that you would get back together or did you basically decide to move on with your life>? and then she came back?
So let me ask about the phone thing, was there another person she was involved with that caused the separation? Was/Is her phone, fb, etc passworded? Do you feel she kept secrets from you during that time. Is the phone thing now a trigger for you because of how things went down previously? A reminder? Obviously it was an issue that never got resolved, just rug swept.
I'm asking cause its obviously an issue for you, and if there was some hiding before, then I understand how it triggers you. Sure, your wife is allowed to have friends and be on her phone, but its what you think she's doing, and how open she is about it that might be your boundry problem.
Letting it slide, right now, yes. But its another symptom of a problem. Does she know how much it upsets you? In all honesty, your allowed to have feelings too, how you deal with those feelings is the other half of the equation/problem here thou.
Your getting a lot of script like talk, your taking a lot of blame, your feeling guilty, jealous, scared, lonely, and possibly betrayed? All natural. I'm sure you have read here the saying "believe none of what they say, and half of what they do". Detach, act "as if" your moving on with your life.