Clare this is one heck of a roller coaster ride you've been on these past few weeks.
Can I just say a word or two about hopsices? In a hospice the care your Mum gets will be aimed at one thing and one thing only, giving her the best possible quality of life for however long she has. They will manage her pain, and help her to have the best possible time to spend with you all. Beyond that, there will be support available for you, her family - people to talk to not just now, but on into the future. Most hospices are calm places with a surprising level of laughter and lots of love. If you are able to, sit with you Mum and share memories, especially funny ones. Play her favourite music for her, make sure that if she likes make-up it gets done for her, her hair brushed, and her favourite clothes or nighty on. There is still time to make more memories, and I firmly believe that she will not leave you until you are all able to cope. Remember she loves you, and that will never cease to be true, and she will know you love her. Hold her hand, talk to her.
Also, be kind to yourself, make the space you need to rant or to weep, whatever you need. You will never find the answers to all your questions, but you will get through this, and one day you will smile again.