Her one complaint was that i was inattentive and didnt pay her enough attention. So my question is, if i detach and roll on, doing a 180, which is ignoring all but business matters, wont that reinforce her thoughts that i was inattentive and did not pay any attention?
While she is involved with someone else their is no hope for you. Affair busting is done by pushing the two affair partners as close together as possible. Only when the bright lights shine on the relationship will it show stress and crack.
Remember that this is all counter inutitive - doing what you think is the right thing is probably wrong.