I am constantly afraid that my appendix is going to burst. I think I read too many Victorian books as a child where this was clearly a common occurrence, and by "clearly a common occurrence" I mean "makes for good, pseudo-reasonable story-drama-fodder." When I moved out of Delaware and lived away from my parents & support network for the first time, I became convinced I was dying or accidentally killing myself a lot. For instance I also became kind of obsessed with the idea that I would choke myself to death on food I was eating, and no one would necessary find me for days. I had roommmates but the house was often empty. - To be fair, I love it when the house is empty. It just also means that if you do fuck yourself up in some physical way, no one is there to help out.
I can relate to your fear of choking on food alone. I almost choked on macaroni once and the fear stuck with me for a long time after. I think it would be undignified to be found dead with a giant bowl of macaroni in front of me and a single piece lodged in my throat.