Welcome here, this is a place where a fair few, myself included, have had to face the death of someone who was a special part of their lives. It's particularly hard with a parent, they hold such a special place and have always been part of one's world up till now.
I learned they remain part of one's life, the fact they have departed does not mean they not are still part of you, they are. To start with I could not imagine anything but feeling loss and grief for ever.
Now I remember all the times together, some good, some bad, but they will always be part of me, and sometimes I even smile as I enjoy the recollection of us together laughing together at something silly.
Would you like to talk about things ? I know it's hard, but what would you like to say abut your mum, not necessarily just at the end, though that's a big part of it at the moment. Later perhaps of times you had together that were good.
I'd also like to ask if you live alone, or are part of a family, and if so how the others are getting on, do they need your help?
I know this is only a short response to one of the biggest events you ever have to face, but I'm listening, I understand, and would sit with you for a while