PLEASE NEED HELP!!!! S7 problems

[tresobb12]

I rooted my device, and did a couple things that involved adding to system files and whatnot. After i got what i wanted done, my Power button stopped working. So to fix it i tried to do a factory reset, that didnt work. I trid to unroot it, i unrooted it but now the market or youtube or g talk doesnt work. I just want my stock device back!!!!!. I was reading something about reinstalling the firmaware, but all the links i tried wouldnt let me download them. I have the best buy american version, if that helps. and i allready tried the hold menu and send factory reset aswell. HELP PLEASE