I'm am so sorry, Sudo, that your daughter died. 
I lost my husband and the only thing more painful, I think, would be a child.
I have recieved a lot of support, but yes, I have noticed lately that the amount of sympathy expressed is trailing off. I think that acknowledging grief and pain is difficult, so people grab onto any reason they can to comfort themselves with the thought that we've 'moved on'.
Moved on, ugh. Hate that expression, and hate that people say it in relation to my late husband regarding my new relationship.
I was thinking the other day that a new relationship after losing ones spouse probably elicits similar reactions that bereaved parents get if they have another child. But of course we can never replace them, and while it's possible to find happiness again, the bone-deep grief never goes away.
I still get sympathy - but it's not quite two years yet. (Dreading that date). But I no longer get many people asking me about DH, or sharing memories of him, which I find incredibly hard. In fact, if people realise the grief is especially bad that day, they often tell me to distract myself, or to put away what ever has triggered the grief. When what I want is the opposite - to talk about what I loved about him and what annoyed me about him and how much I miss him, and to cry and for that to be okay. It's hard to ask for that in the middle of feeling so sad, though. And I do ah e a few people who realise that and do it.
Thank you for starting this thread - it's good to talk about this, however hard it is.