This is so sad for you Cathy1 and it seems that your daughter (along with quite a few other young people) is so wrapped up in herself and her own children (rightly so) that she has has let her relationship with her mum and the wider family fall away. I have seen situations like yours many times where older relatives are almost looked upon as burdens and are tolerated only when they are quiet and don't need any attention which is desperately sad. Now trying to look at it from your daughters side, you say that the grandchildren are lovely and well behaved so she is a good mother. Do you see your grandchildren often? Do you see them alone or with their parents? How far apart do you live? Could there have been a simple explaination why she was unable to come and pick you up from the hospital? Do you have any other children?
I'm sorry I can't offer any practical help as I have no experience of this situation, however I know that young parents have huge demands on their time these days, often having to both work etc. whatever you do though don't fall out with your daughter. Try to keep a friendly relationship no matter how you are feeling deep down. You don't want to risk losing contact with your grandchildren. Sending you my best wishes. Hope you are feeling better, I know what it's like when things get on top of you.