Firstly, don't give up entirely on this year. You obviously got the interest of at least 2 schools. Do everything you can to get off those waitlists. Get a new LOR - a strong one, from a current employer, or someone who knows your work/volunteer experience/classwork - whatever. Send them LOI's, no matter whether you think it will make a difference or not! Be positive, tell them you love them. Keep telling them why you are a great fit for their school.
You could consider adding a few schools to your AACOMAS this year, though it's late. But I know of people that got in to COMP quite late in the cycle last year, for example. It could be a waste of time/money unless you get everything in super fast, but it depends on whether you want to potentially reapply next year if you think it's worth the chance.
IF you don't get in this year, contact schools - especially, but not only, the schools that interviewed you - find out what you need to improve.
Don't assume you know. There will be little to no point to reapplying if you don't improve your application somehow, especially by addressing whatever they say they want to see.
Unless you are really urgent to get started, consider waiting a year (or 2, depending on what you're going to address in your application) and reapplying to US schools. There isn't anything wrong w/going Carribean, but unless you're really a lot older than most applicants (over 35?) you shouldn't feel like you're in that big a rush. 1 or 2 years to improve your application isn't that big a deal, otherwise.
