Breakup speech. やっぱり ('as expected, after all, I thought so') is a flagpole emotional word, marking resigned confirmation of a conclusion. こういうの 'this kind of thing' is a casual abstract reference. 今日を限りに ('as of today, today being the last') uses the formal pattern X を限りに to mark a definitive cutoff point. 別れよう is the volitional of 別れる ('to part, break up').