Despite holding the power to single-handedly save you from an early demise, your son or daughter has declined to maximize societal utility and perform the one act that could keep you from shuffling off this mortal coil. Your condition is terminal, and your prognosis is a last few months of pain and misery. Rather than see you suffer, your family has opted to cart you off to an assisted-suicide clinic in Oregon, where you will drink a lethal dose of barbiturates and pass peacefully into the sweet hereafter.
What music do you pick for this momentous occasion?
I think I'd go with Symphony #6 by Ludwig Van, the Pastoral. It's really peaceful and pleasant, and it would be a stress-free soundtrack to help you ignore the goodbyes emanating from your useless kid's semen-free lips.
I could also go with the 9th, although it would be a very different exit. The drug cocktail only gives you a few minutes of consciousness, so maybe I'd start at the beginning of the 4th movement and hope to make it to Ode to Joy.