Watching my mother lose herself

I am 40 yrs. old and my mother who is 63 is dying. Not solely from the cancer, but the person she was, is and who she thought she'd be. For several years mom complained of small lumps under her arm or in her breast, but always attributed it to "too much caffeine," "cheap deodorant," or "her imagination." I urged her to go the doctor but she always thought "it" went away. December 5, 2010, the doctor found something....a LUMP! Dec. 8th she had a mammogram...the LUMP was a MASS--- BREAST CANCER! Dec. 15th we met with the surgeon. Jan. 13, 2011 was surgery day...the MASS as 4 inches wide and deep and 16 lymph nodes were removed from underneath her arm. We heard the first oncologist tell us that the cancer was stage 4 - spots on her lungs - and it would spread....She felt good/hopeful. Second opinion, Dr. Sitti....we heard her say it was stage 4, spots on her lungs - there will be continuous chemo....mom felt good physically and mentally. We still went shopping, out to eat,laughed at the horrible singer in the church choir. August she feels so drained tired all the time. Days she could hardly get out of bed. Chemo wasn't strong enough, cancer underneath her layer of fat cells on her right side. Horrible outbreak to her skin. She regrettably retires from teaching 3 weeks into the school year. She is lethargic, can't eat, infections began. November 3rd...cancer spread to her liver. Her life stopped. Her mentality was no more. Cancer harming liver but so is the strengths of the various chemo drugs. Looking into her eyes you see blank space. My vibrant, fun-loving, comedic mom is gone, here is now a woman just waiting, learning the stages of the end of her life. She is like a leaf blowing in the wind, following whatever happens until the wind blows no more and she rests. How will I get past not talking to my friend everyday - hearing her laughter - getting fussed at for not giving my kids more candy?