the sooner I stop letting her words sway me the better
That is the key - easier said than done. Now my ex is different than most on here due to her issues, but there is a common underlying theme.
The thing is, when they are in the midst of their affairs, we are nothing - no, make that less than nothing - to them. And that's the key. Sure some come back, but the question of trust remains. For me, once that is destroyed, its damn near impossible to get back. My ex laughed about it and rubbed it in my face...so that sealed it for me.
One of the bigger questions that only you can answer, is how easily you can repair that trust. Because if she were to ever want to try again, for it to work you would have to trust her - and if that isn't at 100%, then it's doomed from the start. Now, not to offend anyone but this must be said, there are some weak enough to allow them back if that trust isn't fully there - just to have them back.
The biggest question is, how is that trust regained? Sure, there have been discussions of transparency and all...but when that trust has been broken to that degree, how is it regained? I mean, in the back of our minds the question will always nag us if he/she is really going shopping alone, etc. That's human nature, especially given that an affair is such a slap in the face. But the nagging doubt will always be there.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.
