Unfortunately, for international students, it's hard to get private loans unless one has a cosigner who is a credit-worthy US citizen. This is one of the major haul international students (like myself) have to deal with when applying to medical schools.
The only other way of securing a loan is through your government. This works best for those in Canada. The worst case scenario is that one could defer and figure all that out in the gap year. However, the institution has to approve that reason for deferment. It's sad the current "status-quo" when it comes to international students and finance.
I wish you all the best with all your endeavor and that it all works out.