Saying no to sex is her choice of course, but if she's made up her mind and isn't even willing to talk about it, then IMO she's already checked out of the marriage. All you've got left is a living arrangement. The emotional divorce has already occurred. All that's left is to complete the physical divorce, which comes down to filling out paperwork, dividing possessions, and handling child custody intelligently.
I'll recommend two books that should help you a lot in coming to terms with your situation:
Too Good to Leave, Too Bad to Stay by Mira Kirshenbaum and
The Good Divorce by Contance Ahrons. Both should be available on Amazon and probably in bookstores too. The first book will help you diagnose your relationship issues and decide what needs to be done. The second book is something to digest if the result is that you decide to break it off amicably.
If you're still ambivalent after reading the first book, then I'd highly recommend reading
Should I Stay or Go? by Lee Raffel. That book is about how to initiate a controlled separation, which I think would be ideal for your situation if you're resistant to divorce.
Although I've read all these books, I've never been separated or divorced. I'm just a very curious person.
The path ahead of you will not be easy no matter what you decide. Just know that regardless of your wife's choices, you deserve to be happy... and to enjoy plenty of sex too.
I think if I went a month, let alone a year, without sex, I would explode.
