First college baseball is hard - really really hard. Most here who have not seen their kids play college ball don't really understand how hard it is.
I wish I could give this a thousand likes. College baseball is hard. It's certainly not easy. If it was everyone would do it. As it is only one in 10 that play HS ball play at the college level (JuCO, NAIA, D1, D2 or D3).
Tribal -
FWIW - my son wasn't offered and didn't commit (to a JuCo) until May of his senior year. He actually signed on the night of the district championship.
On top of that imagine his shock when he sees 50+ players at the first practice. He could have quit right there. He saw it as a challenge. He did well enough in practice to earn a starting spot in the lineup (DH) even though he was recruited as a 1B. His sophomore year he earned the starting spot at 1B though on occasion the coach had him at 3B, DH or OF.
He played well enough to be noticed by several D3's and a few D2's. A D2 eventually made him a nice offer which he accepted and earned a starting spot there as well. He went on to earn JuCo Regional recognition and conference/regional awards at the D2 level.
There are going to be challenges in HS and college baseball just as there are challenges in life.
And once a college student-athlete, it's like having two full time jobs. First as a college student and then as an athlete. You'll find if you read enough of these threads, college athletes have very long days - even in the off season. Days start well before sun up and go well beyond sunset. My son's days typically started at 4 am and lasted until 10 pm when he finally hit the sack. That included early morning workouts, then class, quick snack if he was lucky, practice, dinner and then classwork.
I do know the feeling of disappointment. Despite having a great baseball season at the D2 university, his scholarship was not renewed (grades slipped). At that point he decided to hang up his cleats even though the coach still wanted him. We couldn't afford to send him there without the scholarship aid. It was tough for us to accept, but it was his decision. We had been watching him play for 15 years. I still don't look at a baseball field without some pangs. Looking back, I would do again. It was a great 15 years. Probably the best I experienced.
As to your son's disappointments, about all you can do is to encourage him to pick himself up, dust off and try again (if he so chooses). We all get knocked down at some point. Those that persevere often go far (even if it isn't baseball). Remember, baseball is all about managing failure - much like life.
PS - my son went back to JuCo, earned his Associates and is currently working on his Bachelor's at another university. No, baseball isn't part of the equation anymore, but the challenges he had in baseball helped prepare him for the challenges in life. And yes, his mother and I still love him.