I think the value in this thread does not come down to the ability to help the op. It comes down to hopefully someone reads this and takes the advice offered up before it's too late for them. I will be honest, sometimes I look back on when my son's were playing sports before the HS years and I cringe at myself. I valued some things over other things then and now that I look back I say "What in the _____ was I thinking?" I did some things and I look back and I am quite honestly embarrassed. Just think about this. When your son starts HS at 14 or 15 in ten short years he will be in his mid 20's. For the VAST majority of kids who play sports will it matter if he started? Will it matter if he could run a sub 7 60? Will it matter if he had a good arm? Will it matter if he could hit a breaking pitch? Will those things matter at all?
Ask yourself what will matter? What will always matter? What is really important? What will he need when you are no longer around? What will matter when you can't help? I go back to what is the REAL purpose of sports? What are you really hoping your son gets out of the experience? Would you rather your son be a MLB player and a total jerk? A MLB and have no relationship with him? A MLB player and is not a good man? Etc etc etc? Yes it's possible to have both.
It's a lot easier to look back and have proper perspective. The problem is the damage is done. Yes you can learn from your mistakes. But isn't better to learn from others mistakes? I know one thing it's a lot less painful.