Hi OP, sending love and solidarity. So sorry for your loss.
My own darling mum died when I was 22, she was 48. She never got to meet my kids, and it still brings me to tears when I think of how much she'd have loved them and how much they'd have loved her.
Grief is awful and I also felt, at times, that I couldn't bear to live without her.
But when it came to it I didn't want my siblings to go through another loss. I stayed alive for them, mostly and I'm so glad, now, that I did. I also knew that my mum wanted my life to go on - she wanted me to thrive and live. I'm sure that your mum would have wanted you to carry on without her, for your boy, as well.
Your son will always need his mum, just like you need yours. And I hope that you'll dote on your own grandkids someday, like your mum did, and tell them all about their lovely great-granny...
Sending all love to you. It's so awful but I promise that it does get better.