Thinking about the Emily rhyme line...it wouldn't have to be a perfect rhyme, especially since this is a kind of "unstable" theme. A less than perfect rhyme (say "Slipping away so easily") would support the instability of the theme. And "easily" suggests it's gone before you know it, sort of.
A thought. There are scads of rhymes and near rhymes possible. I just made a list of 42 and quit there. Rapidity, sentimentally, detrimentally, lucidity, inexplicably were among the best ones, I thought. Besides "easily".
Vicki