I am right where you are, (with the exception that my D was final in July) and I struggle with how "well" to get along with my ex for the sake of our 3 young adult boys. It is such a delicate balance. My kids would like my ex and I to be able to spend time together with them as a family. So far, I have been able to explain to them (because my kids are older than yours) that I am still trying to find my center and heal from the D. They "get it" but the long term goal for them is for us to be able to spend time as a family. This is what my ex wants too, which sort of bugs me, and seems like cake eating for me at this point in time. All about making him feel better and all. Maybe I will feel differently later on.
It feels to me like "making nice" with our WAS or ex is what IS in the best interest of our kids, but it also feels very difficult personally. I know there are times we need to be most concerned about our own mental and emotional health, or else we won't be any help to our kids. That being said, in the overall picture, a "healthy" relationship (whatever that looks like)with our ex's or WAS's seems like it is best for our children, especially when the WAS is able to keep their end of the bargain as in respectful, responsible behavior.
I also think how we pave the way, along this journey, with respect to our children witnessing our treatment of our spouses, is important IF R ever occurs down the road. IF R is in the cards in the future, we want our children to be able to be able to be a part of the R process too. 25yearsMLC describes this in some detail in her own experience. She and her H R'd but their kids weren't quite as on board having witnessed the tough times through the separation phase.
At any rate, I think you bring up a very good point of discussion about the value of in your words, "rebuilding trust so that he can be more present in their lives". I agree with you that we, the LBS can be seen as the obstacle in this, as unfair as it seems. I am like you, and can't separate the two different relationships as they are so intermingled. It's sort of like "taking it for the team" and when the team and the greater good is for our children and their well being and emotional health, now and for the future, it gets murky.
As for witnessing the depression.....I am again, slightly ahead of you in this process, but I am absolutely, sure there is depression in play. The WAS is not having the time of their lives. Recently, a family friend connected with my ex for lunch and later described my ex as: "a sad, lonely man, who works all the time."
Hang in there, Busting, you are asking the right questions. The answers will come to us eventually, when we keep our motives in check. And YES, sometimes we just have to get out of our head a bit......
