A chest protector would probably help, as McDave suggests. In addition to the stance modifications others have already suggested, a shorter bow may also help. The angle of the string is more acute at full draw, keeping it a little further away from the upper body. Another option is to intentionally draw the string into your chest/boob, but left of the affected area a little (for a right handed shooter). Then the string has nothing to catch on when you release, or at least not as much. Good luck.