On the issue of faith, I have some very major questions. One one hand, I can't imagine anything as complex as this universe (and possibly beyond) being an accident. But it's easier for me to think of a powerful source rather than a personal God. I guess it's easier for me to tolerate the pain of life if I don't think of it as being "personal", actually directed at me by one who many think of as a "loving" God.
On the other hand, when I read your story all I could think of is how very lucky your husband was to find you. I am a very non-confrontational person and I do not want to cause you any more pain. But maybe this wasn't about you. Maybe you were the person that "loving" God gave to your husband to make his last 2 years on this earth joyful. What would he have gone through if he hadn't had you? Assuming his life was going to end when it did, assuming that was determined, how would he have survived those last months if not for your love?
You see, I'm that person. I really don't have anyone in my life. I have friends but not that person who's world I changed. And I promise you that if I found the type of love you had with your husband, it would be devastating to lose it so quickly. It would make me angry as hell. But it would also make facing my death easier. I could leave with a lighter heart knowing that I'd found true love. I don't know if it makes sense, but it's like it would make my life real to have had that experience. That fact that I may not is actually one of the hardest burdens I am facing as I grow older.
You didn't fail your husband. You did the best you could do as your world was falling apart. What a wonderful thing that your Mom was holding his hand. It was just more love, more that he belonged to you. And the hospice? That's what they are there for. I'd bet 1/2 of the people there "were promised" (hoped) it would not come to that. This is like the couple who have the fight and don't make up before one of them suddenly dies. That one fuss does not negate the love they had before.
And lastly, no, you're life won't be the same. Right now you'll be thinking of him all the time. First thought in the morning, last thought at night. But eventually, the pain will ease. Just try very hard to forgive yourself for any weakness you experienced. That weakness was born of the deep love you had for him. If you'd not been overwhelmed by the pain, you could have been perfect. As time passes, think about the good you were able to give to his life during those months. He was the love of your life. But you may have been even more for him. You may have been meant to be there to give his entire life meaning.