How come guys never approach me or ask me out?

Hi my name is Queenstar, and I’m a 21 year old Ghanaian female and I’m always dressed properly and I’m also very respectful but if there’s something I noticed, it’s that guys never approach me or ask me out and its something I don’t understand. Is it because they don’t feel attracted to me like they do to the blacks, hispanics, and white females? I mean guys always approach and flirt with my female friends, classmates, and relatives. And sometimes it’s guys I have a crush on. I don’t mean to sound jealous or anything. I mean at age 21 people would have expected me to start dating by now. Everytime I see guys I like and I approach them, they say eww get away from me then they shove me away and call me a pest. It’s as if they prefer my female friends and classmate to me and I never did anything to anyone. Whenever i go out I see lots of girls/women being checked out by guys and being called sexy and all that. And when I walk by, they grow disgusted and say they would never date me and If they were to rate me they would give me a 4 out of 10. I’m not that desperate to be immitating the other girls that behave like whores and I’m not showing off my body either. I really don’t want to be a turn off to guys. What do you think could be wrong?