Nina,
So sorry that you are at this point with your mom. Do NOT hate yourself for giving her medicines that alleviate her suffering. It is merciful and she is blessed to have you there doing it.
My Randy also had an end that was far less peaceful than I was hoping. I was praying that God would take him as he had suffered so much. At the end, it was morphine every hour and Ativian and Haldol. I had just finished giving him more morphine when he threw everything up and shortly took his last breath.
Hang in there! I hope your mom's sufferings ends soon and that you find peace. God bless, Sally