Histogram

Also, the histogram doesn’t really matter here. The histogram is just a graph of how many pixels are what value. But it doesn’t in any way record where those pixel values were in the image, and it doesn’t record the style or look of the image. That means there is no way to reconstruct the effect of a preset just from having the histogram. That histogram doesn’t have the right information to do that.

A preset records the positions of the options in the panels, so that is what you need: The files that say how far the preset moved Exposure, Contrast, etc. That information is stored in the presets themselves, which is why the only practical way to apply that again is to restore those preset files. Either from your most recent backup, or by reinstalling them from your downloaded installer or installer disc (which I keep around in case this kind of thing happens).

So a few questions come to mind-

Lost it how?  And what type of Preset? (Develop, Brush, etc)

Have you looked for presets in the [Lightroom] folder?  

C:\Users\{YourName}\AppData\Roaming\Adobe\Lightroom

Why would you be "uploading" a photo that you "have used my preset on" ?   Is this photo you are uploading an original camera file, or a photo that you have Exported from the Catalog previously?  New imported photos will not show any edits.

How is the Histogram involved in this topic? 

How to copy- what? Do you have a preset somewhere?

Remake it?  You can edit an image with adjustments and create a new preset.

I am thinking that if your photo is showing the adjustments (possibly from saved XMP metadata), you should be able to simply create a preset, and all the previous adjustments can be included in the new preset.