I've been subconsciously disengaging and I don't even want to.
I've been having major issues lately with BM and her parenting (or lack thereof, really). It's resulting in SD5 being really hard to handle and I'm having trouble feeling the love I had for her anymore. I've been with my SO for 3 years, so SD doesn't remember life without me. BM and I were friendly at the beginning of the relationship, but in the past year or so, it has really gone to hell. I can't stand her, hold a lot of grudges over her, and have no respect for her way of parenting (not that I show her any disrespect, I just keep away now).
I have been not spending as much time with SD and have pulled the "I'm not her mother" card many times when SO asks me to do something with her. I don't want to do this. I used to love SD almost as if she was mine; I would do anything for her and I loved spending extra time with her. Now it's just more of a hassle than anything. I obviously still care about her, but I feel like the resentment I have for her mother is making me back out of my relationship with her. SO mentioned to me that he can tell I'm pushing her away and that makes him sad because he says SD just wants to love me and I'm not letting her. I don't want her to feel like I don't like her and that I don't want her around. I genuinely don't want to hurt her. How can I stop this feeling of resentment I have for her before she picks up on what I'm doing? How can I separate my dislike for BM from my feelings about SD?
"How can I separate my
"How can I separate my dislike for BM from my feelings about SD"
^^^I struggled so much with this in the past. What helped me was to just change my mindset a little. SD is a child and she did not choose to have parents that were going to get divorced (or separate or whatever the circumstance) She is the victim here. She doesn't need special treatment because she is a child of divorce, but it's not her fault and she doesn't deserve the lack of parenting on BM's part. SD is the victim because she has to live with BM half of the time where you can fully disengage from the BM.
As for your DH, I don't think you should pretend to love SD more than you do. Do what is comfortable for you and involve yourself in what you want to be involved in. Just remember that SD is not BM and she didn't choose this.