I am so sorry to hear your devastating news of your Mum's diagnosis. I can completely understand your pain, worry, anxiety and devastation. My Mum was diagnosed with Kidney Cancer in 2019. She had an operation (cryoablation) to blast it and after nearly dying during operation she pulled through and I cared for her since that time as I was living with her and have been since 2015. In January this year she was told her CT scan showed lung cancer (this was after some stabbling pains in her back and a little cough). In February it was confirmed lung cancer in her right and left lungs and lymph nodes, incureable. No timescale was given and we didn't ask or wish to know. Mum was given a targeted cancer drug for her mutation in March to halt the cancer but rapidly everything starting to go downhill. No appetite, massive weight loss, sickness, extreme fatigue, weakness, bottom sores and deep cuts on her skin, hair falling out. I was losing my Mum in front of me but she still kept going, she wanted to live. In April she contracted covid and immediately was put on a trial drug for people with weakened immune with covid. Eventually she went to hospital and after a week of them giving her the strongest antibiotics they could, she started to respond then the covid peaked again. Mum passed away 1 week after being in hospital with me and my partner holding her hand. My Mum also has had a tough, hard, heartbreaking life and in recent years she was happy and relaxed. 

All the advice I can offer is carry on as you are, its obvious your Mum and you have a very close relationship and you are devoted to her and her care. Thats all you can do, be there for her as much as you can, listen to her wishes, talk to her about happy memories, tell her how proud you are of her, how much she means to you and how you will carry on and live the best life for her too. I told my Mum so many times what she meant to me, leave nothing unsaid. Be strong for her, I did a lot of crying whilst she was alive but I made sure I did most of it in private, I didn't want to make her too unhappy about leaving me even though this was her main worry because she knew how close we were. In a way you will almost do some grieving in advance, I did. Its almost like you are trying to prepare yourself for the end, its awful and I know the pain you will be feeling because I am going through the most awful time now without her and the end of her life was just something that I never wished on my beautiful sweet Mum.

I would also advise to keep up with the GPs, Nurses, Oncologist etc. Some of the hospital staff were not up to the standard of care and compassion that my Mum or anyone deserved. I had to face-to-face complain to the Consultant who told my Mum she could die (no compassion and without me being with her which I asked him not to do and he agreed). One of her nights in hospital she was treated disgustingly by a Nurse when she had to ring the bell to use the commode (she couldn't use her legs). The Nurse was so abrupt and unkind to Mum she made her nervous and she started wetting herself, I have since told the Matron on that ward but I didn't know the name of the Nurse but she knew who I was talking about and she apologised but its hardly acceptable that our loved ones are being treated this way when they are gravely ill. Please make sure you check their names and if you feel your Mum's care is below standard speak out. Make sure your Mum is getting the care she deserves and you may have to fight for this at times.

 Don't beat yourself up if you can't always be with her, you can only do what is possible. You have children to care for so it will be difficult. Thats also what I wanted to say...you have 2 children, they will keep you going in the future, you will live for them and keep your Mum's wonderful memories alive for them too. I don't have any children (sadly) so my Mum was literally my Mum, Sister, Best Friend and Child all rolled into one. Your Mum will give you the strength to continue because your her child and you will think of the strength and courage she has shown and you will also think of what she wanted for you. 

Its the worst path to be walking on. Give your Mum your love and honestly that is all you can do. We are here if you need to talk. Please take good care of yourself and your wonderful Mum.