I hit two low points in my Bills fandom (since the 91 team).
One was a game against San Francisco in what I believe to be the late 2008 season. Rainy, cold, windy, and a terrible game. ***** got thrown on the field, lost 10-3 or something like that and the Lossman played a bunch of snaps. Really bad spot at what I thought was deep in the drought at that point. Worst game I've ever attended. It made me question why I was a fan and spent money on this team.
Then the point in time in the OP. Right after the Rex disaster, shedding all the contracts. "Knowing" we'd be rebuilding and terrible for at least a few years even if things fell our way. It was almost too much.
It just made the end of the drought that much sweeter. I was at the Miami game at the end of 2017, went into the concourse and celebrated with thousands of Bills fans at the game as we watched the Bengals beat the Ravens. (Somehow there was a Bills band there playing the shout song. I have no idea to this day how it was possible lol)
Now we have the makings of a really great team. I didn't know it in 2017 but we had finally hired the right guys after decades of an absolute clown show for management.
I'm in a really good place right now. I'm taking this season as it comes and trying really hard to look past the small stuff.