How I'm going to die is I'm going to be in my little 'ole nursing home, and then I'll be looking up some yaoi fanart and see something so delicious that I start to fangirl and have a heart attack and die. That's just fact.
But if someone came up to me and said "You're going to die in a week; nobody can stop it, but you have the choice of how you're going to die," then it's a different story...
I'd grab some man, 20-ish or so... I'd chain him to a table and, taking my trusty dagger, cut into his flesh just enough to draw blood, over and over again. Over the next week I'd experiment on him in various ways, not going to get into the glorious details here. Then on my last day, I'd take my dagger, prick my finger and let my blood fall onto his lips. I'd give him a sweet kiss on the very tip of his nose. I'd smile at him and whisper into his cut, bloody ear, "Thanks for all the fun." I'd then soak his body, my own, and the room we'd be in in gasoline and set a small fire in the corner. Before it can spread to the rest of the room, I'd finally take the man's gag off so he can scream for help as I take sleeping pills/anesthesia and let myself be dragged into a deep, dark sleep, leaving the flames to eat our flesh, bones, and souls.