I just shot my first deer ever, too, Rick, and i had the very same thought as you, "Oh S*&t, i just shot a deer."  Shot him on the ground, from no more than 15 feet away, with a 4-bladed 125 on carbon shaft, using a yew longbow i just finished.  I was able to stalk that close to him!  As soon as i loosed the arrow, the buck bounded away.  I am sorry to say i could not find it.  It still bothers me.  I had bad dreams that night of wounded animals.  One was a huge horse with my arrow poking out of his shoulder!  Another was my buck but with a whole pile of my arrows in it.  Another, of all my arrows stuck in a post off the property. 
Next time.  You did good, buddy.