Gentleman,
I wanted to share one thing with you from my experience. I saw more arm injuries to players between the age of 13 and 14 than I care to count. My son subluxated (partially dislocated) his shoulder while hitting, elbows, shoulders...most kids rehabbed back, but some didn't. When I went back and looked at the height marker I realized my son had grown 7 inches in 6 months.
All that bone growth and the tendons and ligaments are stretched to capacity and prone to injury. Work hard, but be safe and smart.
Glad to hear you're seeking professional help, but remember, always go with your gut instinct. If it seems like too much, it probably is!
Just my 2 cents!
_______________________
"People ask me what I do in winter when there's no baseball. I'll tell you what I do. I stare out the window and wait for spring." Rogers Hornsby, Hall of Famer