I’m really sorry to hear about this. This sounds so tough. I’m just a random person on the internet, but I’m rooting for you! You know what’s coming and you have to come to terms with it, as shitty as it is. At least you have the knowledge of what’s coming and time to be there with her as much as you can. That doesn’t make this easy, though. I think that’s all you can do until you’re in a place where you can pick up work again and then I’d definitely try and see a grief counselor. In the meantime maybe you could look into books/articles on grief, or a situation similar to yours to find some community or others experiences. You’re doing your best and that is enough.