I am one of the least prejudiced and least racist people I know, but I'm not really sure what you're complaining about. To answer your question in the first paragraph, no, I don't think there is an 'anti black agenda' in the media.
Black people aren't missing in the media. They are actors, presenters, singers, models, everything.
This is one of the most multi ethnic, tolerant countries in the world. But 87.1% of the country is still white. So obviously the predominantly white ethnic make-up of the country is going to be reflected in the media.
The fact is that most people date within their own race. Of course this is changing, and it should, but nevertheless, people tend to stick to their own race. Most people find the features of their own race attractive. If these 'white features' are shown more on TV it's because this is a predominantly white country.
Just for the record, I am a white male and would happily date a black girl.