Roberta - I went through this with my mom just this past June. I stayed with her pretty much every moment in the hospice for the final week of her life. I considered it a privilege to take that difficult journey with her, to answer her needs and be at her side as she breathed her last. Being able to do that helped me find peace afterward and I'm sure it will do the same for you.
You need to make your own decisions regarding other family members, and others have already made some good suggestions. I tried to just put all the JW animosity and ugliness aside and we all gathered together around my mom when she took her last breath, holding her hand, telling her we loved her. Even though she could no longer speak during the final 24 hours, I think it gave her great comfort knowing all the people she loved were there. Death truly is the great equalizer.
Your situation is not the same as mine, but I do understand what you are feeling and going through right now. To as great an extent possible, take care of yourself and lean on the supports you do have. My heart is with you.