Keep in mind OP I have masturbated at work more times than I can count. In peoples homes. When I use to mow lawns one of our clients was a hot milf who always laid in her pool virtually naked. So I'd run into her bathroom after edging her driveway and pound one out. This woman had cameras everywhere but I knew the bathroom was safe. Fuck, if you did a DNA test now 8 years later there's no way her maid cleaned all that shit up.
Then petsmart. When sexy little sluts would come in with their shorts hiked up to their butt crack I'd run to the hamster cage and immediately pound 1 out right into the bedding. Then I'd mix it around so it looked like 10 hamsters peed in the same area. Then my female coworker who was also hot as fuck would go clean the bedding at night and it would come out like a brick of concrete. I also tried to fuck her in the break room one day when she was sitting on my lap but she turned me down. So I ejaculated in her sandwich when she went to the bathroom and went back to work.
The point is, things like this are VERY NORMAL OP.
There is nothing wrong with jerking off at work and smearing your load all over his store and cameras. It's how men claim their territory.
In the same token.... the fact you sound so paranoid makes me think you were in fact torrenting some child porn. Which I simply can not condone. Torrenting costs the directors lots of money. Your IP was probably flagged and I'm sure he's working with the FBI now to get you throw in prison.
Only solution I see right now is for you to confess to exactly what you did. That's the only way the forum can help you right now otherwise we're just shooting blanks so to speak.
Just let it all out.....