How to get rid of this skin rashes?

Hey everyone. Im a 19 years old girl from Malaysia. Im a student, & my class schedule is very packed. From 6 in the morning I wake up, go for class at 8 am. And back home around 7pm. The weather here is hot, I get direct UV sunlight especially around 11am-4pm. I get sweat & so my skin face very bad, because iv been around the campus for about 11 hours without washing my face with facial cleanser. I think my skin face being neglected. So my face started to have rashes around, small spots but not reddish yet its not pimples. People around keep on asking me why my face getting worst. I don’t know what to do or what medicine to cure my skin. Iv told to stop my make up, its kinda embarrassing because I cant wear foundation at all to cover my scar(those old scar effect from the pimples). What should I do with my face?