My mum is dying and I'm scared!

We found out in June this year that my mum had cancer and I was in complete denial! My mum has had chemo and we thought it was positive! The doctor has said my mums chemo is incurable and she has less than a year to live! I had no reaction to this and suddenly a few nights ago I exploded! I wouldn't let go of my mum I was just clinging to her telling her to never leave me! I cannot live without my mum she is the person who holds me together and I'm not coping with all these new feelings. I've never been more scared. Anyone else been in the same situation.