Yo,
Chill out man, it's hard to make up what went wrong since you're panicking and your post doesn't really make sense.
It seems like your problem is software based which means that the 1800 that you spent on hardware should be working all good and dandy.
Could you be more specific as to what happened? Also, you could be more detailed with what you have, that is information that could help.
If you want to reformat your computer, as you believe that could solve your problems, you can do that with the USB stick with Windows on it. Not sure of what version of Windows you have but you should be able to boot to it (when you turn on your computer you should have an option to press del to show boot devices.) From the usb boot menu you should be able to reformat your disk drive and then you can reinstall windows again on it.
Don't freak out, computers are not gonna self-destruct just by deleting a thing here and there.