I'm so sorry

My Mom died in 1978 so I know the pain you are feeling. Just know that while she isnt here physically anymore, she will live forever in your heart. The pain will lessen in time, and the tears will mostly stop when you remember her. And one day you will find yourself smiling instead of crying when you think of her.
The firsts are the hardest to get through. First birthday, first holiday, first anything.
What I've been doing for years which has helped me is to do something special on my Mom's birthday. My Mom loved ice cream, and so do I. So I mark her birthday with a maple walnut ice cream cone and I spend the time sitting and just thinking of her and the happy times we had together. It makes me feel close to her on her special day.
Maybe in time you will want to start a tradition of your own.
If you ever feel like talking, I'm just a PM away. *hugs*