Heavy- I'd like to offer some advice regarding your in-laws.
My situation is pretty unusual in that I have maintained a good relationship with them so far. A few tips for you...
Assume good intent. Yes, they haven't reached out to you. You can look at that as fact their taking sides with your x, or you can look at it as them not knowing what to do or say. In complete fairness, I don't think if I were in my in-laws shoes, I would know what to do.
Regardless of the status of your marriage - they are family with your children and that will always make them your family in some respects. I try to actively think of them that way. It really helps guide decisions.
I continue to acknowledge their birthdays and holidays because its the right think to do and its important to my kids that we do so (and my STBX does not help them with this). And - I'm the one that sets up Facetime chats etc.
Also - I wouldn't assume her family is one monolithic entity. They are individuals - some will probably just assume they need to take a "side:" with her - but others may take a more nuanced view.
