Hi @Stressedoutmummyof3 I'm replying quickly but I have read all your posts.
Maybe our bond wasn't as strong as I thought.
This is probably the key. I am one of 4 children, I'm the eldest. I would have said we were relatively close as a family, all quite different personalities but lots of commonalities too, same type of education, career aspirations etc. Live in different parts of the country for the most part but would enjoy each other's and our DC company when we meet. Family and connection means a lot to me. I am divorced after a horrific marriage, some aspects of the abuse still endure, I've 3 DC, really no support, a good job but still struggle financially (due to crap exH). My siblings are all very well-off and successful and in happy marriages, two are particularly wealthy. They provided no support or exhibited any interest in all the long years it took me to get divorced and really never ask if I need help.
Anyway.
Despite all that, I still felt we were a close family. My DF died some years ago and it is like all the connection that was there has fallen apart. I think I feel it most acutely, as I crave it, I guess. But I think it's not really there with the others either, they don't care as much, they do probably see each other more as their kids are closer in age and they are more on the same lifestyle wavelength too (e.g. can afford a shared weekend away in Center Parcs or similar).
It's really bothered me - and it was my counsellor who said to me 'the connection was never really there in the first place'. Once my dad passed away, my DM changed quite a lot and is really difficult, very cold and hurtful to me, rarely wants contact, shows no interest towards me (even though we were extremely close in my childhood and earlier adulthood, I thought) and has a strange dynamic with everyone else - some are favourites, others play a different role so I think we all get a different version of her. Fundamentally, she is very unhappy herself and she takes that out on me, as I'm the one who can't really do anything about it.
So with my DF dying, and my DM changing or leaning into certain behaviours, the whole dynamic of the family shifted. And now it's like there is no true connection. I get extremely sad about it sometimes.
We still meet up - really just once or twice a year, at Christmas / anniversary - and it's fine. I enjoy their company, care about their DC, happy to chat. But there is no depth and limited contact outside of that, unless I make the effort. When I feel low, it really really hurts.
In relation to your own situation I wanted to share mine as I think it's a version of the same thing - your bonds weren't strong, and so the dynamic shift caused by the death of your mum has probably had this effect. I know it's really hard, but there is probably very little you can do, and only you can decide how much effort you are willing to make.