Great advice given.
Broaden the target lists; spend money to raise the test scores. Have a plan if your scores are static.
I don't know if you're taking the most rigorous HS curriculum your HS offers. If you dont know, ask your Guidance Counselor. If you're not able to check that box, unless you're the single best recruit, admissions will be tough.
While "demonstrated interest" isn't a factor in Ivy admissions, stopping by a school for an informal meeting with some coaches does put a face to an e-mail; if you do that, have your academic resume in hand to give out. The coach may be able to give you an indication of its viability.
As others have noted, admissions is somewhat of a sliding scale (i.e., a 95 mph pitcher has more academic wriggle room than an 88 mph pitcher).
This site has a large number of posters with actual knowledge of the Ivies; so, ask away and good luck!