I've only just read this today and I'm sorry you didn't get any replies. Perhaps you could re-post on the SN board? I say that because I have had such encouragement from some wonderful people on there.
Firstly, I would say your reaction is pretty normal (and it took those lovely ladies over on SN to tell me my reaction was normal too). We found out just over a year ago, when my DD2 was just over 2yrs that she has impaired vision that will deteriorate and she will eventually be 'blind'. My whole world fell apart and I felt that our lives would never be 'normal' again. I grieved for the things my DD would never see, I hated myself for being able to see, like if she can't see then I don't want to either. The future terrified me and I felt very lonely, I didn't know anyone with a child with VI and I think our family just couldn't cope talking about it.
A year on and I still have days where I remember 'that conversation' with the doctors and I feel a gut wrenching sadness, but these have become less. I still have days where I want to scream 'why my baby?' but again these days have become less. I suppose I've come to realise that it's my DD2's 'cross to bare' not mine and that I need be be strong for her.
We have a QTVI (Qualified Teacher of Visually Impaired) who works with DD2, us and Nursery. I've found her to be a valuable source of information, guidance and support. If you havent been referred to a QTVI already you can contact your local council's sensory impairment service and ask to see one, or you can ask your DD's doctor to refer her.
The RNIB website has some personal stories from teens and adults telling how they have coped with they're vision loss and tbh I found them encouraging and there is also a radio programme (that I can't remember the name of, will find out and get back to you) you and your DD could listen to.
I hope someone else can come along and offer some more advice for your DD. My DD2 was only 2 when we found out and has been VI since birth, although due to an injury around a year old the vision in her right eye has deteriorated drastically, she doesn't really know any different. TBH my DD2 amazes me every day, she's such a brave little girl and just gets on with life.
Re-post on SN, I'm sure they will be able to come up with some wonderful advice, as they did for me.
Hope this helps pinkmama, sending you and your DD much love.