Is your EFC actually 0? It’s hard to believe that you have legacy status from two good schools and yet your parents’ income is so low as to have a 0 EFC. If they have income, savings, or assets but still can’t contribute to paying for college, that is different from having a 0 EFC and offers you get from schools will reflect that.
Also, you may need to factor in your own earnings from your jobs/businesses. Schools may view that money as something you can pitch in to help pay the bill.