Perhaps you can access this 1965, Lerner and Loewe lyric movie with Bulgarian subtitles? You must watch the movie in the spoken English, a language which of course, not being British, you probably speak very well.
That will teach you how to pronounce your I's and E's and Y's, never be afraid to exaggerate in front of a mirror.
As Eliza might have said, in the beginning but not by the end, 'that'll learn yer.'
