If your brace height and nock point is set where you tuned the bow, then like kennym says you just maybe are peeking,(dropping the bow arm down and away) Try a few shots just focusing on the target and nothing else, hold your bow arm and release hand after the shot as if your still trying to make the shot(for a few seconds longer)see if that changes impact!
What is your bow weight and draw lenght? with this info we can look at spine!
If you bare shaft tuned your bow to where your bare shafts and fletched arrows impact the same, then we need to look at other things,like above!
have you changed anything, ie. glove,new string, added different string silencers, brush buttons, rest material, tip protector! Is your serving slipping?(this you will notice if your nock has moved up or down from your tuned setting) is there seperation in the serving?
I feel your pain as I have been down that road, sometimes we just have to step back take a deep breath and start from square one!