My mom has cancer/tumour

Hi all, this is my first post on reddit but I feel like this would be a good place to vent and seek support.

My mum(55 years old) has just told me that she has either a cancer or tumor, she is waiting for the result but it is confirmed to be either of those. She is my world and I (16M) don’t know what I would do without her. The thought of her diagnosis makes me want to break down but she keeps reassuring me that it should be treatable which is what the doctors think.

I am young and have never gone through a time where someone so close could have limited time with me and I don’t know how to process these feelings. Thanks for anyone who has bothered to read this but I just needed to get this off my chest.