If you haven't done so already, sit down (I mean with pen and paper) and honestly evaluate your skills and your academic goals. If you have the grades to go to a DI and you have the skills then maybe that is still an option. I know high school seniors who didn't settle on a college until their spring season was over. I think it is rather a common thing. You might be behind because some showcases are over but there are uncommitted showcases for high school seniors.
JUCO is a very good option for many talented players. The competition can be quite good but the real advantage goes to skilled players who need to get their academic feet under them before transferring to a four year school. NAIA and DIII offer other opportunities especially for those academically gifted.
At this point I'd recommend researching schools you think would fit your skill level (in other words do you want an opportunity to play right out of the gate -JUCO, DII, DIII or is it ok to redshirt or sit the bench one or more years -DI). Check out each school's internet website. Email the coach and/or fill out the prospect questionaire and wait for a response. Go see the school and if you can get a tour and talk with the coach, most likely the pitching coach or recruiting coach do that.
Be aggressive in your research as if you are looking for a job but be realistic when you talk about your skill level to prospective programs. Don't exaggerate how hard you throw, your pitch repetoire or previous stats. Find a program that fits your desires and get them to see you. You should be willing to meet them anywhere to throw for them.
If your grades are good and SAT or ACT gives no pause for concern then many doors are open for you. Just pick a few and walk through them. Once you get inside you'll know if the room feels right or not.