There's no way to 'unreset' (if it is reset) unless you have a blender save from some point before you did any editing.
I'm guessing here, but did you make a copy of the original and worked on the copy? If you did (more guessing) did you link the copy to the original? (CTRL-L from your 1st post) If you did, you followed not-so-good advice, but I have a fix. If my guesses are right.
Meanwhile Hana's right:
This is your problem. You should have the UV map. But by following incorrect advice and doing CTRL-L you linked the original with your copy (if you made a copy to work on) so when you edit the copy, the original gets "borked" right along with it. I have ideas how to correct it, if that's the case. If I'm wrong I'd still like that cookie for trying to fix my/your imagined problem.
If none of that made sense, just do this: Get 2 pics: one showing your entire model selected in edit mode, and one of your model's borked UVs, to satisfy my crazy curiosity, and to show Hana you're listening.