In Speaking English^x, British people^x

QUOTE: I am living in Saudi Arabia, which there are few native English speakers it is hardly to find them easily. There are lots of English people in Riyadh. If you live in or near Riyadh you should be able to find English companies. Speak to them and tell them that you want to practice speaking...

I just wanna know what I can do in order to understand British accent. I speak American English. I realized that I cant understand British accent at all after seeing The prince and me and Harry Potter. Why do British people sound really bad? or I dont think they are speaking English haha.