Yes, definitely tell your Mum. Tecoyah hit it on the nose - she NEEDS to feel that she is there for you and supporting you. Besides, it's way too huge a change to go through by yourself.
Don't kid yourself - it's scary and hard and awful, even when you get good results. And no, it's not going to be very easy on your family. You may even feel guilty for everything they will go through with/for you. But never doubt that they WANT to be there for you through this, and they don't care how hard it is. Who said being a family was easy all the time?
Let your Mum be your family.
I wish you all kinds of luck and positivity and good things. I have a lot of family that's gone through cancer issues - the most important thing you've got going is you. Your attitude makes a world of difference.
I wish you well (in every context!!).
