The truth is, no one can tell anyone if they will get in, yet get merit money. There are kids with scores like yours that have done well - got in and with some merit, and others with those scores that haven’t even been accepted. Yes, that is true. There could be someone just like you from a larger more competitive school, or that wrote a killer/better essay, or that was part of a certain EC for 10 years, and any one of those advantages over you could knock you out. It is competitive and it is holistic, meaning all you can do is try, hope for the best, but never count on a dream school and never ever count on a large merit prize. Not trying to be discouraging at all, you look good on paper, but so do a zillion other kids nowadays, depends on what they need or want that year or when your application passes the desk. So do all you can and apply broadly - a couple reaches, couple safeties. Research will tell you what schools would be financial safeties for you (where larger scholarships are most likely). At USC that is too hard to call by any outsider, particularly when interviews are involved.
Also remember full tuition is tuition, there is still room and board and other expenses associated with going to college. Certainly your parents are going to step up to some of it - hope so. Substantial merit aid from any school is achieved by being at the tippy tippy top of the students applying not just with grades but with extraordinary ECs or circumstances. I frequently reference the student applying with super scores to aerospace engineering who was already a pilot as an example of this.
This is a great thread here by @madbean:
Good luck!