My dear friend, well, I am a person born in Chinese (Cantonese)-speaking Hong Kong, formerly (co-) of the British, where the English language were sole official for half of the life of I (mine), and now co-official, yet I still have to spend 11 years and another 4-and-a-half years in England to simply get a score 7, so, with respect, my advice is to spend 5-10 years of the life of yours in an country of a state where the English language is native (and stop speaking other languages), otherwise there is absolutely no chance for getting a score 8, I am so sorry.