1994 Chevy S-10 Loss of pressure

Today when I came to a stop I felt the break pedal drop to the floor really slow, like letting the air out of a balloon. I went to an empty lot and can still break however it only 'works' when the pedal is completely against the floor. There is no resistance whatsoever. We checked the break fluid and it is still at a good level. All break lines were replaced 3 years ago. There has been absolutely no noise coming from the breaks when coming to a stop. This issue came out of the blue with no warning. The emergency break light came on when this incident happened and will not turn off. The E-break itself still works and there is no obvious fluid leaks.

Also, I don't know if this makes a difference but when the truck is in neutral and the e-break is on, if the break pedal is pushed down it causes the engine to kick up a bit. I've never noticed this happen before. It's not necessarily revving the engine but you can hear a kick in the sound.