You have obviously gotten some excellent advice. And what stood out at me the most was what UR said:

Just let things be for a while. Trying to figure out why the way things are isn’t always necessary. Especially if it’s something we can’t change , even if we know the why.
I also understand that you feel like you can declutter your thoughts if you figure things out and can pack them away. But it’s OK to leave things mentally “unsolved” I think the reason why I feel lighter these days is because I am sitting in the present and not looking for the why’s so much.

You have gone through a lot of loss lately and it’s a lot to unpack. I know family dynamics can be complicated. Especially at the time of a big loss. And I think the best thing for you, might be doing what the best thing for you is. Make sense ?