Hard to see but it looks to be a 4.5 5.5 year old giant of an old buck. I'm not great with my scoring but looks to be about a 170. That close you should have had another arrow ready to fly if needed but heck he dropped like a rock so I can see why you wouldnt. To bad you couldnt find him. That kind of thing happens though, keep hunting hard you will get another chance and know just what to do.