So sorry to hear about your mum.
I still live in the house my mum and I shared and even now, more that two years on, I still find it odd not seeing her about the house.
This is a tough period for anyone following a loss. There is a huge amount of things you have to do and trying to do them whilst the pain is still so raw and unbearable is an enormous load to bear. I did find it helped me to write on this website. It helped to know others understood what I was going through and made me feel less alone and that helped somehow, even though the company was remote and virtual.
Try to make sure you eat a little and drink enough. I found that was something I had trouble remembering to do in those early days and sleep was a problem as well. It does slowly get better, but finding a way forward is hard and takes a long time. I think a lot of people who lose someone close and haven't been through that before expect to recover from it in weeks or months, but it doesn't work that way. It takes different people varying lengths of time to find their way forward from such a personal disaster in their lives. For most it takes months and for many years and it often gets worse before it gets better and grief is a nasty slippery slope that you have to help yourself not to slide down, because it can be overwhelming, like mud, once it gets a hold on you, it can be very difficult to drag yourself out of it again, so I would advise that you take it slowly, a day at a time. Look for anything that helps. For me it was having flowers around and sitting on a bench in the park, where it was calm and peaceful,so i could try to absorb all that had happened and come to terms with it in my mind.
I also found it exhausting, so I needed to find a way to have a break from it sometimes and to do that , I took up a new interest and joined a class, so that I had a reason to go out once a week and had something to look forward to.It made me engage with life again and forced me to think about something else. It also meant I had other people to talk to, some of whom I found understood what I was going through, having experienced it themselves.
You will find your way forward from this and it will get better, but be patient and be good to yourself as you nurse yourself through this. The immediate pain will dull with time as acceptance grows and the shock recedes, but once you are a grieving person, I think you will always be a grieving person and sometimes you will find the sadness back with you for a while, but it will lift again and you will have better days. You learn to live with it.
I found it also changed me as a person and I have never been who I was before it happened since. It changes your outlook on life and your priorities. It makes you see things differently and approach life differently, so there is the new you to come to terms with being as well.
It is a rocky road, but it does lead on and no doubt, your memories and love for your lovely mum will always remain in your heart to sustain and guide you through your future. They have for me. I still hear her advice in my mind when I don't know what to do about something, my dad's too and he passed away over thirty years ago now! Your loved ones never really leave you because they are a part of you and always will be. I find that a great comfort and it will do for now, until we meet again.
Wishing you well.