Hey man,
Don't be too hard on yourself. It happens to most everybody at one time or another. Several years ago I took a shot thru a hole in the brush and spine shot a buck. He dropped like a rock and I couldn't see him from the stand. I thought "he's dead but I'll give it 30 min. just in case". After I waited I got out of my stand and went to where the buck went down. He wasn't there!!!!!!! I looked around and saw him about 50 yards away dragging himself with his front feet. I had to finish him with a second arrow and it made me reflect on what I was doing bow hunting. I didn't bow hunt for a couple of years after that. I'm shure 2" lower and he would have bled out in seconds but that's hindsight now. I'm a better hunter now and have learned some valuable lessens from this. Get back out there. Good luck.