I am not one that knows you personally, but I am so very sorry for your loss. Having gone through my own cancer treatments I know it's not an easy thing at all. I lost my mom (she was 63) after she got sepsis after a "routine" surgery. I was released from the hospital after my thyroid cancer surgery, and went directly to the hospital she was at. Saw her and she passed about an hour later. It all happened so fast, and I miss her every day.
People say it gets easier, but honestly if it were easy then to me it means you didn't care. Try to focus on the good times you had with your mom. I am hoping you have a great support system in your friends and family. If not, please feel free to give me a call at 267-471-5612 if you need to talk.
Chris