What can you tell us about your learning style, and the kind of accommodations you need? Would you benefit from a formal autism support program? Would a co-op based program, where you get to alternate classroom learning and real-world work experience, be appealing to you, or would you prefer a more purely academic experience?
Do you want to do marching band in college?
If you like UCSD, you might check out UT-Dallas, which I think of as culturally and academically similar but which has some generous merit scholarships. (Although their best scholarship packages are for National Merit - did you take the PSAT? Your ACT scores suggest you might have had a shot at a high enough PSAT score for NMSF.) https://honors.utdallas.edu/
Appalachian State might be worth a look. Full-pay OOS COA is around 39K/year but there are scholarships that you could be competitive for. There’s a computation track in the math major. There’s a terrific marching band. And there’s an autism-themed living-learning community.
As others have noted, the UC’s are a non-starter cost-wise. The separate application for the UC system is onerous and with no path to affordability, it’s a waste of time.
You have a fairly long list of private universities that meet full need; however, it sounds as if you may not be able to afford what the financial aid formulae say you can afford. Have you run Net Price Calculators for the specific schools on your list? (Your net cost will vary - the FAFSA SAI is just a starting point, and each college has its own algorithm for how much aid you’d get.) Yes, you can appeal, but getting more aid than the NPC projects cannot be counted upon, and you’d have to appeal every year, with some risk that your school wouldn’t be as generous in subsequent years. Going someplace with guaranteed, renewable merit aid may be a better bet for you. Also, landing outside the top 10%, class rank wise, makes the single-digit-acceptance-rate super-elite schools less likely. If you look at the Common Data Set that most of these schools publish, you’ll see that only a tiny percentage of entering students at some of these schools ranked below the top decile, and it’s likely that many of those were “hooked” in some way, e.g. recruited athletes. It’s absolutely fine to shoot your shot at some uber-competitive schools, particularly at ones where the NPC results look good, but you’d really have to beat the odds to get in.
You might check out the Honors College at the University of Utah. UofU offers a path to residency after the first year, as well as merit scholarships, so it could be affordable, and it has a very strong math department. Excellent music opportunities too.
IMHO, the most likely outcome here is that you attend an in-state public university, as that’s the most straightforward path to affordability, there are excellent options. (Is there a reason you don’t have Clemson on your list?) But OOS publics with generous merit may also work (this would not include UIUC or the UC’s), and it’s not impossible that a full-need-met private U might give you enough aid - again, run the NPC’s and see how it looks.