Hi. I'm 30. Male. Been working at this job for 5 years. I haven't been able to sleep very well due to some guilt, and the fear of being punished for something I did at work. It's been a rough few weeks for me. 

I have not actively told a lie. But I have knowingly withheld information that I probably should have mentioned. 

I'll try to cut as much detail as possible: 

I use a machine at work. The machine has been giving me incorrect results. These results are not necessarily the end of the world but its slowing down production overall. At first my boss said that there was no other explanation than me simply feeding things in to the machine wrong. I knew I had been doing it correctly, but I went with it since I couldn't prove it. 

I let my supervisor (my boss's wife) observe how i put things in to the machine, and she herself acknowledged that it was correct. So they are getting someone to come take a look at it. 

However...I started to think on it, and I have a feeling I know what's going on. A physical adjustment of the machine had been made at some point. To do this, someone would have had to unscrew a certain bracket, shifted it, and then screwed it back down tightly. It's not something that can happen by accident. I do have memory of grabbing the wrenches we would use to make such an adjustment. And I do remember being at the machine with them. 

This issue has caused a certain degree of setback for the whole workplace, despite us being able to remain on schedule as usual. It's not a night and day difference, but it is a difference. I think my boss would have a right to be upset if the repairman comes and he points out that someone must have moved a bracket. 

I've kept quiet, even though I really think at this point that it must have been me. 

***Humor me for a moment****.* Let's say this is exactly the case. Let's say it was 100% me who made the adjustment and caused a bunch of frustration for everyone. Let's assume this is already the case. It's going to feel like a lie no matter what I say. If my boss says essentially "You are the only one who uses this. How else could it have moved?", all I know to say is "Yes, it must have been me. But i don't remember doing it." That sounds like such a lie, considering the deliberateness of such an action. I've also thought about saying "Well, I can't contest it", and just accept whatever judgment there is. I feel like I'm having to rehearse this whole thing the way I'd rehearse making up excuses to my teachers why my huge book report wasn't finished. 

It's really eating away at me, especially considering my boss has a temper. He isn't this generally angry person by any means, but when something goes wrong, he's short fused. I remember one instance where he opened the door to the room as was in, saw what I was doing, laughed in this "you've gotta be kidding me" sort of way and walked off. He's coldly told me my work "looks like shit" and that I need to redo it until its right - only for everyone to realize it was due to the materials I was given. He has hollered at other workers when he didn't see enough products coming down the conveyer belt. I've heard him clapping his hands, and laughing, saying "I can't fucking BELIEVE this" in response to some other workers. I do not know the context. 

The point I'm making is... I just want a peace of mind. Just a little peace of mind will do. I feel guilty. I'm sure it was me. And that's a conclusion I come to even in my most sober states of mind. I want to be able to find contentment even if something bad happens to me or my job.