Re: a rom i got from here corrupted my entire
I'm going to second the idea that the equipment is likely faulty. I've personally been using this site since like 2000 and I've never had so much as a hiccup that might suggest the roms from here are corrupted or anything of that nature. Vimm is pretty thorough about checking and maintaining quality. If anything I'd say the emulator you mentioned could be the culprit as a quick google search yields some less than safe looking sites offing it as a download
It doesn't matter what you did before, my 64GB Micro SD Card just borked recently and it was because the phone decided to break it. These things do just happen and it's not usually because of a file or folder.