There's no shame in stopping. Sounds like you were hypothermic, which is a common reason for DNFs.

From my experience, I would say that you wouldn't have been able to continue even if you needed to.

Also, always beware of the spectrum. Some people would say running for 17 hours is impossible. Others would say they shivered uncontrollably at 17 hours and roughed out 3 more hours before dropping. Others still would hit 24 hours and wish they could keep going.