Black people and skin color issues?

Okay, i am a dark skin 17 year old black girl. Ever since i was in elementary. Kids would make fun of my skin color, call me black and ugly. While the lighter skinned wouldn't get teased. People would tell them they have a beautiful color. I would often go home and cry, I hated myself!!! I use to pray and ask God to make me brighter. It got worse when i got to middle school. I'm currently going to be a senior and when i was in class one day. My friend said she don't want a dark skinned baby. "If i get one I putting them for adoption." (she's bright skinned) I got offended. People would come up to me and say. Hey! you're pretty for a dark skinned girl. That would offend me also like dark females are suppose to be ugly. Also I currently date a light skinned male who loves my mocha brown complexion. But a lot of his ex's and female friends would say why u go with that dark girl. She's dark and you're light!!! Why are people like this? Why can't people see that beauty doesn't have anything to do with skin complexion?