Anyone who has hunted very long has made poor hasty decisions. I've done it a time or two. And not just while hunting, in every aspect of life!
I don't know what to tell you about the deer. You may or may not find him, but either way you have learned a valuable lesson. Have a plan and stick to it. And just as important, know your equipment. Spend a little extra time at the range so you don't have to wonder how long it will take to load.
I'd say the MOST important lesson to be learned is that you need to keep pouring the lead to 'em until you KNOW that they are finished and aren't going to get up.
I don't know why I have said all this, because I'm sure you figured it all out on your own already. I do hope you find your buck (I'm guessing he's piled up in a brushpile nearby), and I hope you get a chance to get back out soon and boost your confidence back up. Take care, and good luck the rest of your season.
rw