I too was like this for quite some time. Once I learned to let go of the anger it became much easier to have a PMA around her.
It can be done. I don't have any type of trick or method that I can share. I can only say that when the rope is truly dropped then this comes naturally.
Me:43 Her:42 M:14 S:9 EA started 2014/03 (or there abouts) PA started 2014/05/30 BD:2014/11/05 I left 2015/10/01 I returned 2015/05/02 She left 2015/06/10 OM still on the go.