SDSU is a California public university. It is funded by California taxpayers and the State of California. Your guidance counselor should have informed you about the costs of California public colleges. Privates colleges charge the same fees for everyone and tend to have more private monies for scholarships and grants.
As a public university, SDSU’s priority is to educate California residents, and, as a public university, it doesn’t have thousands of dollars to fund non-residents. Such that
students from out of state pay full fees because the State cannot afford to pay for non-residents.
If you were admitted, it means that they liked your profile, but they also assumed that you would be a full paying student.
If you filled out a FAFSA, you will receive ~$6K per year from federal funds and can borrow about $6K+ per year from the feds, but that’s it. You would still owe $30K per year plus health insurance fees (which are separate).
If you are at $0 income, you wont be able to borrow this kind of money.
Jobs are at a premium and wont help you to make this kind of cash for 4 years without a degree.
Please look at your safeties or wait and reapply next year to the California privates in the area like USD and Point Loma Nazarene. There is also Chapman University in Orange County, Loyola Marymount, Azuza Pacific, USC, and the Claremont College Consortium.
Edited to add: our Community Colleges would also be full fees, which aren’t as much as the Cal States, but you would have to pay high California rents. Plus, you would still be considered a non-resident and would still have to pay $42K for two years because you would be noted as being in California for “educational purposes”.