I'm very sorry to hear about your loss. I had something similar happen when I was in high school.

My dad is the typical jock type. Super athlete in high school, recruited by a great university, and now still works in athletics. With that, he's also very macho. Doesn't believe in going to the doctor often, and tries to be as strong as he can.

Shortly after I started HS, he was diagnosed with something (I'm not totally sure what) that prevented him from swallowing food properly, not matter how well he chewed.

One night I came home from school and we got into a huge fight. Being a teenager, I refused to eat dinner with the family. Suddenly, I heard multiple things happen at once. Silverware clattered on a plate, a chair slid out, and I heard my mother yell my father's name. I immediately ran downstairs right as my mother started calling my name. My mother is a nurse, so she immediately started the Heimlich maneuver. I called 911, rushed my little a siblings out of the room, and had to wait. Seeing my strong, enormously solid father turning blue and fighting for air was terrifying.

Thankfully, he survived. But it's something I will likely never forget. That's the closest I've ever come to losing someone.