I don't understand anything

A fews minutes ago i'was watching a documentary over about ["over" in this context is common in French/Spanish/etc. but wouldn't be used this way in English, at least in American English] Donald Trump. I began watching in english with subtitles english too. I read perfectly and i understand english reading, i can translate in french instantanetely instantly or instantaneously [instantaneously is a little strange in casual context] so many words, and for that i'm glad. However i don't understand american accent, at all! According to me, american people speaks soooo quickly, it's a nightmare. Of course i know i have to practise my "hear" "ear" or "hearing" but i don't progress at all. If anyone has advices for that .. [emoji]