Worst case scenario: Wing being sheared in half, (I can't remember the example, but its happened once or twice in flight due to heavy turbulence). It would be that disgusting feeling of knowing you were going to die 100% in about 2 minutes. I always wonder though if I might be so freaked when it happened that i'd get a heart attack anyway!
When I was flying GA
aircraft, worst situation for me was idea of having to abandon (we carried parachutes as standard) - the idea made me feel sick, especially as it had happened for real a few times over the last decade to others in the service...ugh.
As for realistically, spending an entire 14 hr flight from SIN
with a bad back and having the back of the seat kicked constantly by an annoying woman behind me.
Sorry to hear about your loss Womack17!