Bummer. I did similar, but mine booted fine thankfully. I can’t seem to get newer drivers to install, and suspect this is for a reason.
If I were you, next step would be to plug in a keyboard and hold down erm.. F8? Or ESC… Whichever is the key that Windows 8 uses to get the special boot menu up. It should allow you to restore/recover or select SAFE MODE and from there you’ll be able to work on it further.