I hope you're okay...I crashed my car a few weeks ago so I know what kind of pain you can be in afterwards...I was in so much shock afterwards I could hardly string a setence togehter nevermind sit an exam, so good on you.
I don't know how likely it would be for them to give you a grade now, but I think if you write to them they will at very least mark your first paper sympathetically (sp?). And they'll probably look at your situation more kindly considering you showed up and made the effort.
Good luck getting it sorted, hope you feel better soon