Im an African American teen and I have been trying to stop liking white girls now for quite some time How do I overcome this horrible habit?

If you are in a school that is predominantly white, don't worry about it. You will be attracted to people that you're exposed to on a regular basis. If you are in a equally mixed or predominantly black school, you are fixating. At this point in your sexual development you are forming your future ability to relate to women. A fixation can turn into an obsession and you are at a point where you can gain control of that.

I am not a psychologist, so if someone with those skills is available to answer this, please jump in. In the event that doesn't happen, I will suggest that you start thinking about the girls you are attracted to as people. People like your family and your friends, not just the object of your desire. When a girl attracts your attention, observe what you might like about her in addition to her appearance. Does she have interests that you can relate to, does she like the same classes (or not) as you, what does she like for her free time, does she participate in a sport or a have a hobby, what activities does she do with her friends? Get to know these things about her (or them...) and you will be able to discriminate who might actually be suitable to spend some time with.