My Mum has terminal cancer

I feel like my whole world is crumbling around me. My Mum has been diagnosed with terminal cancer. Pancreatic cancer that's spread to multiple organs. I feel like iv already lost her and everyday I'm grieving for all the plans we had, all the plans she had with my 5 year old son. She's 67 and we was meant to get many more years. I'm wanting to enjoy the time we have and make memories as a family but I'm finding it so hard to just make it through a day without crying. She's my world and the rock of our family, I don't want to imagine my future without her in it.