Oh I am so very very sorry. You did everything you should and it just isn't fair. It sounds like you really loved each other so much. I wish I could help.
I am very sorry the hear of the loss of your beloved husband. Hopefully you can find the strength and courage to get through the coming times. Find peace in knowing that he is no longer suffering, and he is whole again. Allow yourself time to grieve and be mad, it is only natural. Comfort can from from many different sources, like this forum. You and your family will be in my thoughts and prayers.
Please accept my deepest sympathy to you and your family on the loss of Robert. When the loss seems to be overwhelming you, look up Lisa. Our Father is there for you and Robert is now in His tender loving care.
Lisa, you have my deepest and most sincere sympathy. I hope you take comfort knowing that Robert is now the arms of God and free of pain, and that we are all here to support you.