More Questions about Great Expectations

My question has to do with the new characters Compeyson and Arthur. In Chapter 42 on pages 348+349 it says that Arthur sees Miss Havisham in a vision and is deathly afraid of her. So deathly afraid, infact, that he ends up dying having a dream about her. My question: if compeyson is pressumably Miss Havisham's lover, and leaves her on the altar, why is Arthur so deathly afraid of her instaed of Compeyson?