I have a tumour! HELP!!!?

I have a tumour growing on my gall bladder and according to the doctors it is growing extremely fast, I am due to have my gall bladder out this month so they can test the tumour to see if it is cancerous! The doctor has told me if it is it would be secondary cancer as a tumour can not start at the gall bladder and it will also be somewhere else! I am sooo scared I don't no what to do, I am only 20 and they is my worst nightmare as cancer runs in my family! HELP!!!!