Softbricked HTC One M7 - How do I Revert to Stock?

[mglowa]

So i installed Cyanogen mod and after awhile i wanted to go back to the stock Sense. I followed the instructions for reverting back to stock by installing RUU but it did not work. I am stuck in bootloader and any option I pick there does not seem to do anything. Looks like there is no operating system installed. What do I do? It also may be a problem that I started doing all this without checking the USB Debugging option- couldnt find this option anywhere inCyanogen. Please Help!! Thanks

Phone is HTC One AT&T