It’s a little concerning that you just let the deadlines go by without even being entirely sure about taking a gap year.
Look, not going to stomp on the choice you’ve made, to each his own. I’m sure (or, at least hopeful) that you’ve put a good amount of thought into this.
A good reason is the key to a successful gap year and, honestly, wanting a higher SAT score and having missed the deadlines just isn’t good enough.
Wanting to get into Stanford as an international applicant isn’t something you can just count on. No top 10 school is ever going to be a surefire thing; you could bring your SAT up to a 1600 and still easily not get in to a top 10 school next year, either. Unless you’re curing cancer during your gap year, it’s going to be very hard to get in.
What are your grades? Extracurriculars? This isn’t a decision that can just be taken lightly.
If you want to leave your country, why not just apply to a more reasonable US/UK school that will still take you? Then, you’ll have grades and measurable accomplishments for that year, and, who knows? You may not even want to transfer.
Several schools give you until 1/15. I recommend you try that out, instead of just taking a gap year and praying for the best, because what happens if they don’t accept you that time around? At the very least, throw in some applications to realistic schools, so that you’ll have more options come Spring, should you change your mind.
USC is still open, although, unfortunately, a 1320 won’t be good enough, unless you have some cool other stuff to offset it. Just, keep researching. This isn’t something you can decide on over the course of a day because you ran out of options.
Best of luck to you!