I am not sure why you would be shooting short.  When shooting from an elevated position, like a tree stand, you will typically need to shoot a little low, depending on the angle of the shot.  At 37 yards, there shouldn't have been any noticable difference in where you should have aimed.  I don't mean to insult you, but I find most problems can be solved looking first at the easiest solution first, are you sure you are using the right site pin?

Good luck.

Bob

  Do you use a peep sight? Are you bending properly at the waist, or improperly from your upper body? Are you dropping your arm at the shot to watch arrow flight? Try experimenting with lower elevations in small increments. Start at five feet and move slowly up and note the results. That's all I can come up with. Good luck!