Feeling lost

How can life carry on when the person who gave you life and was your life, has passed on? I am merely existing with no purpose anymore. I miss my mum more and more each day and the frustration of knowing that nothing is going to bring her back is more than I can bear. I wish I had gone instead. Or at least, have gone with her. Even now I wonder if we did enough. Did we not fight for life as much as we should have? Should we have not taken the Drs at their word and fought for further action? It torments me so much. I'd give anything to go back and change things. When I did voice my opinion, I got shouted down by nearly everyone and I felt I was being unreasonable insisting more be done but I wish I had. The guilt I carry is awful and the fact I never took mum's hospital bag to the hospital when she had asked me to leaves me with even more guilt. I bet she was thinking that I didn't bring it up because I knew she was going to pass on but after the call from the hospital I just rushed up there but it wouldn't have taken long to have grabbed her bag, it would have given my mum some comfort, that she will need it. But no, I didn't take it and I arrived at the hospital empty handed. I'm so sorry mum. You asked for it straight away and u felt awful. Did I think you were going to pass on? Is that why I didn't take it? I can't bear it.
I'm never going to hear your voice again. Never going to cook you a meal, or ask about your health, make you coffee, take you shopping, go bingo, all of what we used to do. It's so hard. My only consolation is that I will be with you again one day in hopefully the not too distant future. I don't like life anymore.