If you're an illegal Mexican but you graduated from high school and 2 years of college in the USA how can you work or stay here legally?

No. You can not work or stay here legally. Your best option would be to look for an employer in your field (one according to your college degree if you graduated), who is willing to "sponsor you" (apply for an employment visa for you). You may have to leave the country (the USA) in order to come back in with your employment visa.