This board is full of posters whose son has
- increased his level of competition,
- faced new challenges that caused them to struggle,
- made an adjustment to their game
and exited on the other side a better ball player.
You said your son has moved up to more of an elite travel team. In other words, he improved his level of competition. If I had to guess, I would bet that your son is now seeing better pitching.
Continuing my guess, I’ll go a step further and assume that due to your son’s size, he’s seeing more spin and / or more fastballs away with fewer mistakes over the middle of the plate.
It may be time to work on identifying the adjustment needed at the plate.
Take him to a youth field. Grab a bucket of balls and play a game of home run derby. Just see ball...hit ball mentality. Have some fun with it. It may not fix the adjustment needed but it should be relaxing and fun. Since I didn’t provide a feel good story, let the home run derby be the beginning of your own feel good story. The story has to start somewhere