Your story suggests that she still love you. Depression can, and will often, lead to a feeling of uselessness and things like that. When I am in a depressed mood, I try to hide from others as much as I can, because I am so unhappy with myself. I guess your wife has something similar. I think for now the best thing you can do is to keep showing her your love and care, and get through this together. When she is ignoring you, the chances are pretty high that her depression is ignoring you, not her. So making it very clear that you love her and no matter what she does you will always be there can be such a great help.
I believe that one day you will be alright, and everything that happened will be worth the effort.
Have a wonderful day!
Acceptance is the key
The World is but a reflection. Smile, and it will smile back.
Try to keep smiling! :)