Actually, I think you are right - you can connect with other people whose experience resonate with yours, but it is something other, something much more, to find people who exactly understand.
For me, the important elements of my experience are Catherine being a person - with a personality - who was embedded in and was a huge part of my life - in fact all the important bits of it. I really miss her. I feel aggrieved for the loss of her life, because I know how pissed off she would have been to be dead. And it especially hurts that given she was really here, she existed that so many other people seem to be ignoring that fact now.
The other element for me is suddenly not being a parent any more. I was one and now I am not. But I can't be unmothered - it's not like I don't know what it is like to be a mother. I have heard people use the expression childless parent - but I have never met or spoke to someone in that position. I have no role - it's like my whole was stolen with my daughter. And then there is my age and the implications for having another child... just having another child is huge - as you say... and I have that, but also don't know if I even have that option.
I had a long convo last night on fb with a nice mum who'd lost her son the week before Catherine - and that was really helpful, because we're sort of at the same stage.
You are right - it wouldn't need to be real life - it would be just amazing to connect with someone who faced the same problems as me.
I do feel very alone. I come in here sometimes, and people are chatting about their DCs or gran kids or whether to decide to have a baby next year... and I feel so utterly alone.. sometimes it is just all too much.
The problem is - there's a lack of even basic support.... if we wanted really targetted support, not sure how it would be best to get it... Perhaps we could start a facebook group for parents who had lost DCs suddenly I suppose...