Oh my goodness, I am hugging you as I write this post. Your sadness is overwhelming and no words have been spoken or written that can help right now.
Try to find some comfort that Rob is well now and out of pain. He is complete again and waits for you. When you see him, it will be as if you have never been apart. For now he would want you to continue your life until that day comes. He is with you every minute of the day and night, but the physical Rob is missing from you. There is an empty space in your life, but never in your heart. Keep his memory close, keep a picture by your bed, talk to him, and the tears will flow for some time to come. For now put one foot in front of the other each day. He knows how sad you are and he will try every way to comfort you, but it may be hard to recognize his efforts at this time.
It is right to feel angry and hurt. To love someone is to feel those things when you have lost them.
One last hug before I leave you, my dear. Have faith that you are being watched over every minute of your life and how much you are loved.