In this section, it is very important that you are totally aware of where the upper melody is and that you make it as prominent as you possibly can. What I find works best for me is to separate the upper and lower parts and practice them on their own, while at the same time imagine hearing the part I'm not playing.
For me, this technique of practicing always helps me to get much more of an understanding of how the composer wrote the piece and also what the composer really had in mind whilst composing it.
You will notice that the opening motif returns here to close the piece and the important thing is that you gradually decrease the volume until virtually nothing can be heard. It may well take a bit of practice to get it right as it requires a lot of control. The idea behind it is that by the end of the piece, deep sleep has been achieved!
Best of luck with it and as always be sure to post your take over in the forum for us all. Night night, Sleep tight!