You are properly concerned about the quality of your education. A bachelor's degree from a very low-rated school is not much help for getting into grad school if you eventually aim for advanced degree(s).
However, financial aid for foreign students is scarce (often unavailable at all), and competition for such funds can be extremely tough. A few countries have scholarship programs for citizens to study abroad & bring back needed knowledge & skills for the country's development. E.g. India has such a program, but is now almost exclusively for advanced degrees as bachelor's degrees are now common.
You can only work your way through school in your country of citizenship. All countries severely restrict or outright prohibit work by foreign students. Even where limited work is allowed, most foreign students never find any job. The "lucky" few who find part-time jobs quickly discover they cannot earn enough for either school OR living expenses after paying costs of working (taxes, uniforms or proper attire, transportation, etc.). Also, you must prove you have sufficient funds for all school + living expenses + return transportation to your country of citizenship to apply for student visa. No money = no visa.
Research & apply for all the scholarships you qualify for. If accepted by a university, apply for financial aid if they have any available for foreign students. If you were accepted at a good school, your parents might loosen their purse strings! Have another discussion with your parents on costs to see what they can afford. And work! American kids often start earning & saving money by age 12-14 for their future college costs - long before they can get any job! Look for part-time jobs & other ways to earn money while you're still in your country finishing high school.