So.....you were high, adjusted your pins, and now you're low? Am I reading that correctly? Sounds like you over corrected. Now, why were you suddenly hitting high? Many possibilities. Your sight moved. Your rest moved. Your peep moved. Your string stretched. Your cable stretched. Or maybe you just weren't holding right.

Make sure everything is tight. If you have access to a scale, see if the draw weight has changed. If your string is stretching, it will gain weight. If your cables are stretching, it will lose weight. Then make sure the bow is tuned. Make sure your arrow is level and centered.