I think this is what is known as catastrophic thinking. I'm very familiar with this. lol

So change it up, think about how they know now so that might a good thing. You won't have to feel stressed out about them finding out or you being "discovered". They already know. This could relieve some of your stress in that you won't feel like you are hiding something, keeping a deep, dark secret.

It sounds like you are really good at what you do...so continue to be that, to do what you've always done. I have no doubt that you will be compensated it. Don't let yourself go down the tunnel into worst case scenarios...I know, easier said than done. But keep trying to see the positive and just keep being the hardworking, productive employee you've been.

Good luck!