You are a Physician. It gave you great pride to recite the Hippocratic Oath at the end of your training. This oath, which dates back well over 2,000 years, has been the source of medicine's ethical creed ever since. The Hippocratic Oath defines the role of the physician. It says the physician is a healer, and only a healer. The Oath states in part (and here you can quote), "I will give no deadly medicine to anyone if asked, nor suggest any such counsel." You swore to uphold this oath many years ago. It is an oath that has been sworn by generation of physicians. You will not bend from that resolution now.
In your view, the healer has no business ending life. It disturbs you that so many of your medical colleagues are now so willing to weigh one life against another, choosing which of those lives has more value or less. Doctors are healers, not gods.