I am so sorry for you loss. I am really close to my mom as well and even though we are in different states, I talk to her almost every day and can't imagine losing her. It would be a huge void in my life and I would cry every day too.
She is schedule to go to the Mayo Clinic on October 12th and hopefully we can find out what is going on. I know the doctor had said the cancer was aggressive, however, I need to find out exactly what kind it is. We are all very skeptical, including her doctor about the cancer being gone. He is very confused about all of the test coming back negative for cancer. I will have her ask the people at mayo about the vit C as well.
I wish you the best and thank you so much for your help. I will let you know what happens.