My dog was diagnosed with cancer more than a year ago. Sasha, then a six-year-old golden retriever, was limping heavily on her daily walks and had stopped making the frenetic puppy runs she did whenever she was let off leash at the park. At the time, we assumed that she had pulled a muscle and would improve. Weeks later, after a battery of tests — all of which she endured with the affectionate stoicism other owners of retrievers will be familiar with — we received the diagnosis.

We had two choices: amputate the leg and try to prolong her life, or let her live as long as possible, as comfortably as possible — until it came time to put her down. While initially amputation seemed the better option — Sasha wasn’t old by any stretch of the imagination — there was a high probability the cancer would return despite it. Fearing the trauma she’d feel after losing her leg, we took her home and bought painkillers.

I had a year to prepare for the inevitable ending, but as it approached, I found myself putting it more and more out of mind. I couldn’t be a present, loving owner to Sasha while dwelling on the fact that next Thursday at 10 a.m. she would be put to sleep. As the day approached, I found myself increasingly struck by the strangeness of knowing the hour that a creature you loved was going to die. Sometimes I questioned the decision not to amputate; often I hoped that by some miracle Sasha would wake up the next morning the dog she had been only a year ago and we could indefinitely postpone her death.

My parents announced around the same time as Sasha’s diagnosis that we would be selling our house in London. We’d spent the better part of 10 years in the house; I went home for school breaks there, studied under the willow tree in the backyard, knew every kink in the staircases and could tell you what time of night it was by the sounds I heard outside my window. It was the last of my childhood homes that I still visited, all the others having been sold.

Both in the case of Sasha and the sale of the house, I had to live in the shadow of certain endings. Not cataclysmic ones, but small, aching changes that will come and are impossible to stop. As a senior, I am also facing another certain ending: a conclusion of my time at this institution that, like my house in London, is home, intimately and profoundly.

My struggle has become balancing a desire to live this moment, with my dog, in my house, at my school, while wondering how many more such moments there will be. In a strange way, certainty is the harbinger of uncertainty: On the other side of a known ending lies an unclear future.

While the certain future is limited, there is at least the illusion that you can shape the time you have left. The world presents both more opportunities and more anxiety on the other side of endings, a thought I am working to find exciting instead of chilling.

Ever the control freak, I have only a matter of months to learn how to let go, put the dog to sleep and cope with both certain endings and uncertain beginnings. I am searching for ways to forgive myself for not always being in control and, more importantly, to learn how to forgive myself for not always being able to save the things, people and places I love.

Zoe Mercer-Golden is a senior in Davenport College. Her column runs on Wednesdays. Contact her at zoe.mercer-golden@yale.edu.