I think that some good advice has been given to you so far..
I have a close friend w/ the same problem as you. I do not know your hunting distances or conditions. For him in our conditions, he has relegated himself to only taking neck shots on the deer. Granted most of our shots are taken on deer feeding, standing still, so that is a big factor.
The shot that seems to work the best is a "quatering to" shot that is placed in the neck right in front of the shoulder. It will usually take out the neck (spine), airways, bloodvessels, portion of the vitals. If placed correctly, it will also disable the shoulder on the opposing side as it exits. If they don't fall in their tracks, they should drop in sight for sure!
In the years I've known him, I've only had to help w/ 2 deer!! One was an easy retrieve w/ a very good blood trail, other was a little harder, but the deer was still recovered... His C/B is so bad he couldn't see lung blood on a blanket of just fallen lemon yellow leaves...