I have occasionally homeschooled each of my three, for a year or 6 months, that kind of thing, so I know how much you have put into his education, yourself. Congratulations on raising a wonderful young man.
We all have trouble finding balance between honoring our kids’ autonomy and still guiding them when needed (if tolerated) toward the end of high school years. I understand you wanted to let your son direct the college application process, and he may have just taken the reins.
Honestly, I would say that applying to all reaches the first time around was not good judgment, not because of the possibility of being stranded so much as the lack of knowledge of the wide range of schools that his choices showed. For instance, check out the Colleges that Change Lives website (and book). Some of those schools are also consistent in approach with homeschooling (Hampshire for one, also add Marlboro, Bennington). There are also schools like Bard and Oberlin that are selective and a bit alternative. We loved Clark, which is on the list. And for science, many of the UC’s would probably be good, including UCSD.
To apply to all reaches the second time around, including some of the same schools, after being rejected, defies reason. Sorry, but it really does. I feel for him and for you. But why is he so stuck on prestige? I would look at that. Does he need validation after homeschooling, does he need to feel legitimized? Has he felt marginalized in some way ? There must be some reason he is only applying to these top schools because it is not, on the surface, reasonable. Is he afraid to go to college and sabotaging his chances of leaving?
I know this is not why you posted but maybe your jitters are related to what you know to be true, that he has mismanaged his applications to some extent. Of course, a second application shows persistence and he may very well get in- I hope so!
We all feel a lot of things as our kids reach this point. I personally found the leaving of the oldest to be the hardest. When I left him at college, it was just hard to believe. And coming home is never the same again, it is true. Even though many do come home!
Some of us have kids with health challenges or other challenges and worry a lot when they leave. But even without those, this may be the hardest thing you do in your life: letting go. But I would also caution, don’t let go too much! You will struggle with the rest of us to find that balance. Good luck!