Anything I can do or did my stupid mistake screw me completely?
Edit: Cant even get into recovery mode
When I got my Sprint S4, I thought I was cool since this was my second Android phone and I had experience with custom ROMs and rooting on my old phone. So, I got cocky and in a hurry and managed to flash a T-Mobile ROM on the phone. I had a small heart attack when the T-Mobile logo appeared during boot. Anyway, using ODIN, I was able to quickly get the stock Sprint setup back on the phone and start over. You should be able to do the same thing. If you don't care about Knox and want the latest, just try this thread, and you should be all fixed up pretty quickly:
If you're worried about keeping an older bootloader things will be more complicated.