I saw your post a couple of days ago, and have wanted to respond, but took my time. I am just home from the hospital. I had a surgery to have a very large ovarian cyst, as well as my appendix removed.
For what it is worth, I feel you are very brave. I admire your strength. Although you originally posted asking for advice on how to end your life, I feel, in a sense you are choosing life and I am very proud of you. I should probably explain a bit...
My surgeon is part of a huge network of teaching hospitals here in Toronto. He was concerned about how quickly my cyst grew in size (within a few weeks). THis was worrying for him. I had to face some difficult things in the last few weeks and determine what I wished him to do if he opened me up and found invasive cancer. When I told him that in the worst case scenario I wished him to leave me intact, close me up again and let me direct future action, he said, "that is like NOT choosing life". I went home and thought about that and decided that I felt that I was precisely choosing life by honouring myself with that decision. I am aware that there are vast rooms at these hospitals with rows upon rows of people receiving chemotherapy treatments at once. To me this is not choosing life.
I can only understand a little of what you may feel at this point. What I do feel is that you desire to honour yourself, and so you should, in whatever way that may manifest for you.
Someone else here recommended Andreas Moritz ' new cancer book. I think that is probably good advice. There's another wonderful book which never leaves my reach. It is called "The Path of Practice" by Bri Maya Tiwari. In it she describes her own terminal cancer diagnosis. SHe had many surgeries and many treatments that did not help her. Finally she decided to retreat to a friends cabin in the woods in Vermont alone. THere she prayed, cried, sang, recorded her dreams, and wrote a lot every day in her journal. She basically went there to die in peace, but when she returned to the city, still alive, 2 months later, all traces of cancer were gone from her body. SHe turned her life around then and dedicated herself to honouring her ancestry, her cultural traditions and the rhythms of life. I wonder if this may be inspiring for you.