I am truly sorry for your loss. This thread is quite a godsend, I think. Knowing that it is a shared experience by so many, does help to heal. As my Mom died very young, I got to raise my much younger sister, as a result. So, her death, unfortunately, became a constant daily reminder. The fact that my sister turned out as well as she did, though, was always a testament of my Mom, for me. Her body may have left, but her spirit always remained. And, to this day, the best part of my sister and me, is my Mom.
Give yourself plenty of time to grieve and avoid people around you who are not as solicitous as they should be. And always remember how truly fortunate you were to have the time with your Mom that you did. Nobody can ever take that away from you.
I'd also add that there are many places where you can do a tribute to loved ones that have passed. That is also a great way to heal.
Many of us have mothers up there who are welcoming your Mom, as we write.
Hugs to you.