Not to be too gloomy, but it's really stretching reality to define today's game as a "must win." The Phillies are not going to win a wild card berth. What happens in the rest of this season's games is pretty much academic. Grasping at straws about theoretical combinations of the Phillies winning out, and other clubs (multiple other clubs) collapsing is just that - grasping at straws.
Probably better to just accept this, rather than getting worked up over the next week or so, as the Phils win some, lose some of what you imagine are "must win" games.