I've had the EXACT same feeling in my gut for over a month now....Waiting for the "Big Fail". As a 34 year fan of the team, I’m preconditioned to feel this way, just as you mentioned.
It’s my mind trying to protect itself from the possibility of the collapse. It’s the primal "Self Preservation" feeling and I just can’t shake it. It’s such a powerful feeling, its keeping me from enjoying the ride.
It’s both a Blessing and a Curse….Its Glorious Torture.