Here's what I have done, and do, with my kids - 9, 11, 13. No matter what happens out there - if you go 0-5 with five strikeouts or give up 8 runs without getting an out or get just a pinch hit at-bat, I really enjoy watching you play and am proud you're part of the team.
When they succeed by overcoming adversity - holding it together through a blown "save", I let them know the best part of the game to me was seeing how well they handled that
For the kids I coach, I let them know it is part of baseball and I know they will do it next time. "But Coach I can't." "Yet", I add.