There is also a huge generation gap. I live in a generation that there is no shame going to counseling, reaching out for mental help. My parents, that is another story. THEY WOULD NEVER. So many times they just do what they know, ignore the problem until it blows.
I myself will admit that when I was married to my XAH, I did not want to include him, nor did my family. You did not know what you would get. He turned many many holidays into misery. So I get that to some extent.
I second what Lexie said, look elsewhere for your own support. It's not very likely to come from his family, who are surely feeling a lot of things, I imagine guilt is in there pretty heavily for them.
It's sad, but it's nothing you can change. Many, many hugs.