Thanks for your comments.
So this and many Nocturnes tend to repeat quite a lot, as you say the middle and end is very similar, and the start also repeats so my first piece of advice to this piece is learn it hands together!
As the rhythm stays the same almost the whole way through you need to get your left hand under control straight away so that you can focus on bringing out the melody. Furthermore, as a lot of the parts are very similar every time you practice this piece you are very quickly reinforcing the technical skills required to play it comfortably.
With the middle, i'll be honest I did find this quite difficult, because it's hard to get the top note to sound out which is the melody here whilst not drowning out with the left hand repeating and also with the cresc and dim.
if you really want to break it down first play just the right hand and really focus on the dynamics, it says PP to start, if you have a left pedal, use it, and don't bring it off until you want it to sound at its loudest so you in contrast it sounds loud, but not so loud that it the tops notes are swamped by the rest.
Really keep that left hand quiet also, I find that hard for the part that starts on the Eb's so try and also transfer your right hands weight to the little finger.
I think touch and dynamics is the difficult aspect of this piece, and it's something I have to just be content with as I use a digital piano and so can't achieve the same level of touch authentically.