Hi,
First of all, there is always hope, so DONT GIVE UP. Doctors are not bad people but like you said, they know of chemotherapy and radiation and drugs only. There are things out there that you and your mother can do.
My mom also has cancer and I love her with all my heart. I have researched and found wonderful things and success stories of people sent home to die and given no hope. Look, I don't know if you or your believe in God, but with all certainty, I can tell you He is there for us. I was not a believer, I am a mathematician, and like many of us scientists, I found many good arguments to disbelieve. I recommend that you find a book, its called "the lenguage of God", written by the head of the Human Genome Project, needless to say, a rigorously trained scientist, admired and respected by everyone in the scientific community. I know that you are scared and very sad, but this is your mother's battle. She must be willing to fight, even when her strenght is little. Know that its not up to you, its between her and her loving Heavenly Father.
Now, there is a book that you can find in Starbucks, its written by Dr.Norman Walker. Its about the benefits of juicing.I know you are young but somehow get yourself a juicer, a good one. Start making your own ORGANIC carrot juice. Give your mom Organic cold pressed Flaxseed oil, and have her eat raw vegetables everyday. Find the website for Dr. Lorraine Day. She was also given very little hope. Darling, only God knows the hour. Don't get discouraged. I will pray for you, and don't think for one minute that this is nonsense. Pray with your mother, fight, research, people are dying because of ignorance. Don't give up!!! And don't be scared.