Had a similar situation last year. Shot a smaller 8 Pt, at the shot shot my cable slide broke, which operated my arrow rest. Cable slaped the arrow, arrow struck deer in chest, but penetration was limited. Deer ran off, no blood, no hair, nothing. The only reason I know I hit him was I saw the arrow sticking out. Looked that night, the next morning and into the day. Nothing. I went back next weekend, followed my nose to what was left of him. I cut the antlers off and took them home. I keep them as a reminder to check my equipment as well as out of respect for the deer. I killed him, but becuase of my lack of attention to detail most of him went to waste, the other critters ate well though. I would keep the antlers and mount them on a board or do a skull mount. You deserve credit for continueing to look for the deer well after most would have given up. It' s not an easy thing, but it does happen.