Ozy Clint, The problem you are experiencing could not be any more exact than the problem I fought for nearly 2 years. I used to be a good shot, I shot split-finger, have never had target panic in my life, considered myself an instinctive shot and was hard to beat on a 3D range. Then everything slowly started going to hell. I executed my shots perfect, they felt just like they always felt.....except I shot 8 inches high.
I tryed raising my nock point but that was just a crutch and really causes problems if you shoot with a can't like I do. My form had to be good because of the groups I could still shoot.....they were just as good as always, just 8 inches high. I got so frustrated I tried everything even shooting 3 under and while I could shoot good this way I never really liked it as well and knew there had to be an answer.
Then I began thinking......what if my mind was really gapping the arrow.....and I wasn't as instinctive of a shot as I thought I was? If I was unconciously gapping then shooting a 2 inch longer arrow would effectively lower my bow hand perhaps just the right amount.......Bingo.....Fixed. Try shooting a longer arrow and I will bet you will see your groups drop. This absolutely fixed my problem. My draw is around 30" and so long as I shoot an arrow around 32.5" (regardless of arrow weight) my groups are great...but if I cut them to the riser at full draw I am going to start shooting high.
I can also remember through the last couple of years slowly shortening my arrow length to pick up a little speed and stiffness in the shaft. this is when everything began going to hell. It took finding an old arrow I used to shoot that I had filled with foam for weight (and couldn't cut down) for me to figure it out. I was trying to gap with a shorter arrow which made me raise my bow arm just enough to shoot a little high all of the time. My old shooting method (sight picture)was so ingrained in my mind that I could not make myself consistently "aim lower". My mind knew what was right and would not give up. So as Waitingforfall stated...I made the bow shoot where I was looking.
Sorry so long, your problem is just one that I fought and thought I would share with you my findings. I hope this helps. Get a little longer arrow (don't worry about the weight of the arrow for now) even if it's lighter I'll bet you still shoot lower.
Guess I'm not as instinctive as I thought I was.
Good Luck,
Mike