Apologies for not having read the whole thread in detail, but my feeling is that when one has a Big Problem that not everybody can understand, you have to be judicious about who you share it with.
For example, after I had a late miscarriage, it was really shattering to discover that I couldn’t count on my family of origin. I had always had this picture of having a fantastic family, but after my miscarriage and the complications that followed, I realized that a) even people who love you can’t necessarily deal with your problems if it’s not something they understand b) at least one of my close relatives is interested in what he’s interested in and nothing else and c) I realized I had been doing 80% of the heavy-lifting in most of these relationships. Not that my relatives are terrible people, but they were only prepared to deal with got-everything-under-control-and-everything-is-awesome-Xantippe versus Xantippe-who-is-suffering. (That was, by the way, how I originally found CAF.)
Even earlier, when my oldest was having behavior problems and ultimately got an Asperger’s diagnosis, I’ve kept my mouth shut about that to my older relatives (parents and grandparents and aunts and uncles). I have given my sister some books and videos and we have talked about the spectrummy aspects of our family. My brother also has a child who is much more autistic, and one of these days, I should talk to him and my sister-in-law about our experiences, but we don’t bump into each other a lot, and I don’t think SIL is ready for that conversation yet. Our youngest also has an autism spectrum diagnosis. I have never told my grandma, “the girls are both a little autistic” because it’s just not something that she would understand. Back in the day, “autistic” meant just profoundly autistic. I have a local buddy who has a disabled child, and we talk about disability issues, and I talk to my husband, the kids’ teachers and the kids’ psychologist and I talk about it a lot online and with email friends, but I don’t talk to random people in real life because a) I don’t want to argue about my kids’ diagnosis with people who don’t have any background in the subject b) it’s not information they need and c) I want to protect my kids’ privacy. As a case in point, my youngest has just turned 5 and is finally about 98% potty-trained. This is not information that I feel the need to share with the older members of my family. (Interestingly, I am actually more open with my MIL, who has some professional background in dealing with special needs children.)
When it’s a big problem that not everybody is going to understand, there is some point in choosing who you are going to confide in, so that you don’t wind up being exhausted by explaining things to people who aren’t on your wavelength and don’t understand your problem. (To give yet another example, there’s a child at school who has a serious health problem. There was a mass communication telling us that there would be updates, but not to ask for information individually.)