I struggle with the same thing. I have learned that I need to choose my words carefully when speaking with STBX. Any time you use "you" to speak with xW, that is laying blame. Just repeat what she says in a validating way. If she says you do not do xyz with the kids respond with I understand, thank you for bringing that to my attention so I can improve xyz next time.
Not easy, you will be eating a lot of sh$t sandwiches even post D. That is just how the wayward person is.
H-46 XW-38 T-7 M-6 S-9,8,8,6,4 S 11/30/15, I filed 12/8/15 EA 2/1/16 D dismissed 3/24/16 PA 3/18/16 confirmed 4/22/16 XW files for D 4/1/16 - D final 11/17/16 Finally moving forward...