Do whatever it takes to "fix it."
I missed a lot starting out, at 20-25 yards, with both an old Redwing recurve and homemade d-bows. Starting out, I practiced standing up mostly. However, I actually shot at deer crouched down, kneeling, sitting and once coming out of a long held push up position to my knees to shoot, and that particular arrow landed right in front. The three coues whitetails just looked at it. I was not drawing a full 28 inches or whatever. A friend said I missed more shots in the 2012 Arizona velvet season than his work mates had opportunities added together, since they hunted. That season haunts me.
I sympathize.
But, excluding deer jumping the string, edge shooting was a problem. It is natural to look at contrast, like a deer edge. Have you tried cardboard cut out of a deer in front of you target? Push your fist into the cardboard to create crease like on a deer.
In Arizona, does became forbidden when I moved down here. So, I get plenty of opportunities to watch female deer. Train yourself to see the kill zone. I ground hunt exclusively, so I do not know what a kill zone looks like from above, but my first coues deer was 21 yards down a cliff. I hit the spine. Meaning I almost missed.
Keep practicing. And, only three shot opportunities in a decade? I would find better ground.