You sure are taking this hard. I know how it feels to lose one. The only thing you can do is what you are doing. If you truly exhaust every way you can think of to find that deer, you have lived up to your end of the deal.

I think you were getting close. When that deer was making all those beds, he was not able to get comfortable, so he'd get up and bed again. My guess is he's close by to that location, or he will recover. It would not surprise me to hear that you jump him again, from a thicket near that location the next time you are out there. Seriously wounded deer will hole up and just wait until they feel better, or they die.

It isn't deer killing, it's deer hunting. Things like this happen. It's not unethical to continue hunting. Unethical are the guys that don't spend more than 20 minutes tracking deer they hit.