Diamond4---I too am a single baseball mom. My son is a centerfielder and signed with a D11 school, will start this fall. I don't know that I can give you any pointers, but can very much identify with you. I've had those "bruises" too. I feel that I have done my best, I've been a baseball mom since he was 5. I've pitched to him, ran after fly balls you name it... enjoyed every minute though.
From his first t-ball season, some of the fathers said to me that I should keep him on the baseball field, he had talent and he could run. I've done all that I can do to encourage him, support him but I do feel that he's missing something. But as he matures I think that he realizes the things that I have done. I think that missing a father figure in your life is sometime a "mental" thing, although I think he has looked at his HS school coach for alot of "role-modeling".
Congrats on his opportunity at next level, if I can be further help let me know. Just hang in there, that's what I'm doing...