I cannot help with specific suggestions, but have to say I am so impressed with how you’re taking charge of your life, with so much stacked against you and having so little support from your family. And I’m so impressed with this community, with so many people already having come up with so many good suggestions.
From your writing style and your course rigour it appears very clear that your SAT score doesn’t reflect your abilities. Are you getting accommodations? If not, your school should look into that and help you with it.
Otherwise, you’re the kind of student test optional was made for, another reason to relax about this going into this process.
I hop this community will continue to rally around you. I’m rooting for you!