A few weeks ago I sparked considerable disagreement when I challenged the conventional advice frequently given here for players to choose a school where they know they can play.
This thread makes my point more convincingly than I could have. The hard truth is that you can't know you can play at a certain school until you actually earn and retain a starting spot there.
Furthermore, there is no safety in "dropping down"--regardless of whether your idea of dropping down leads you to mid-major, low D1, NAIA, D3, D2, or JUCO.
There is competition at all levels. The roster math is often even more brutal at D3's than D1's, and your coach is diligently working to make it worse. If a coach can recruit you, he can probably recruit another guy as good as you to challenge you for the position you want. In fact, he probably did, and that guy is already a couple years older and stronger than you.
At every level of baseball, the numbers are bad, and they get worse at the next level. You can't run from the numbers. You can only challenge them head on and endeavor to beat them with your best effort.