Brain Mets, I need some advice please.

I have been caring for my mother since her stage IV lung cancer diagnosis in Oct 2012. She elected to receive treatment as she is only 64. Well, it has come time now that treatment was removed and her heart can no longer take it. It has metastasized from her lung to her, adrenal glands, lymph nodes, chest wall, and very large brain mets. She recently has become very angry, yelling at me, telling me she dont want me around, and that I am treating her like a baby. I had to put her medications up as she messes them up every day and it takes me an hour to straighten them up. I am trying to hold my tongue and have patience but I am wearing thin. Does anyone have any advice as I dont want to put her in a home or have a live in nurse? Thank you all in advance.