Never be disappointed in yourself for shooting a deer. He was good enough for you when you pulled the trigger, why not now. Revel in the fact you're a hunter and do something very few would do! It is a bummer that you didn't get to eat any meat off him, but it happens. You tagged him when a lot of other hunters would have taken the head gear and walked off to keep a tag in their pocket... Honorable IMO. Still a good deer!