I never had children, but if I had, I would have wanted them to love me the way you love your Mom. And best of all, you DO get to keep the love, the memories, the thoughts and the feelings forever.
I'm sure that this Mother's Day must be really really hard for you. I remember the first few Father's Days after my Dad died of colon cancer... I would yell at the TV "not everybody has a Dad!" at the commercials. And cried a couple times when I had to walk past the cards instead of picking one out.
Please remember that your Mom will ALWAYS be your mom, and its o.k. to honor or celebrate her if you want to tomorrow or ANY day..
You just continue being the caring, wonderful daughter that you are. I'm sure your mom is just as proud of you today as she ever was....