Climb a 5.11
Be sure your belay is strong enough to alternate between jeering and ropegunning. You are free to scrabble, sweat, and swear during this humiliating attempt. When you have thrutched your way as far as you can, come back down, rest for a moment, then take on a 5.10. In comparison to what you just did, it seems a lot easier and less embarrassing.
Although it sounds masochistic, but it breaks the mental barrier that keeps telling you not to go beyond the 5.10a level.