I think you are confused in believing your ethnicity, or more specifically in this case skin colour, determines what you should think/feel/like etc.
You seem to think that the way you think is "white", hence thinking that you could be a white person's trapped in a black body - Don't be so naive, these things are determined by so many factors.
Stop with the self-hate, you are perpetuating this idea of white superiority which has no biological basis at all. The domination of whites is a result of the social world that people have created, and you are allowing yourself to be belittled by it. The levels of genetic variation between people attributed to different ethnicities can be significantly smaller than those attributed to the same ones - distinct races don't actually exist, it's just physical phenotypic variation. I'm not trying to be clever here, just demonstrating how useless race as a concept actually is, and therefore how little things like skin colour actually matter.
Being black, or mixed, or whatever you may be does not make you in any way inferior to another person on it's own. Similarly, being black does not define who you are necessarily, your skin colour will not in this day and age hold you back from being the intelligent, strong person that you want to be. However, your personal feelings of inferiority will, you need to change these negative ways of thinking. Don't allow yourself to be brain washed, that is definitely not an intelligent thing to do.