How to change all keyframes at once? (Locked: Duplicate Post)

So... I've been working on this college project for a very long time... And now almost all of the mouthrig keyframes hace changed values... Some of them are at negative values... Which should be imposible when I put the slider on 0-8.

I am freaking out.
I am actually more scared than ever before. This project has to be done in two days or I'm going to fail the course for sure. I NEED it to work or I am screwed and there is NO way I can just restart it, I don't have the time for that!