My mother died a month ago. I too am still numb. Mothers are such strong force throughout our lives and when they leave us its almost sureal that they are gone. I believe in my heart of hearts that my mother is looking down on me. My friend asked me just yesterday how I was doing in regards to her pawing and I said I just feel numb.
May I ask how old your mother was?

Mum was 83 1/~2 years old

I am so very sorry for your loss. You are 2 days into it now, hopefully some of the shock has worn off and you have been able to begin processing things. It takes time.

I've lost both parents, in the last 2 years, and it still hurts a bit.

I'm not going to say it gets better, just that it gets different and less painful. Kind of like a new normal. You will find your new normal, but it will take time. I am still defining my new normal, but it has taken a lot of shape now, and my old joys (family, friends, activities, ... ) have come back. Some are "better" than before, others not. Mostly it is just different; my new normal.

Please consider joining the Bereavement group. The people there have helped me through some hard times, some dark moments, we all have our losses from which we can share experiences.

https://www.dailystrength.org/group/bereavement

So very sorry for your loss!