Outside scholarships are tough, but not impossible but for most you will see, likely a waste of time and many are need based. The easier ones to get are the small, local ones - but they barely make a dent.
National merit is awesome - but not for your list (except maybe BU). But Alabama, Maine, UTD, Tulsa, some of the Florida schools and more - it’s great. I think as far as high end and in your area, I know Bowdoin gives $2K and BU has something but not assured…but that’s about it.
But when you are looking at physics, for example, schools like Arizona and CU Boulder punch well above their way and in many cases well above the so called prestigious.
But again, you are early - but - you should have those discussions. You say you’ll pay in full - but what will your parents say. And if you’re only looking near home than that will certainly limit your scholarship ability.
For now, keep up the great work - and if you do get NMF, then it’s just another tool to work with - and that’s a great thing!! You have lots of time before you get into this game.
For now, visit different local college campuses to see what type of environment works for you. No organized tours or info session - just go with mom/dad and check out the campus and area - and take note because again, BU is very different than say, Brandeis.
Good luck