as Abe said
i would suggest that you memorize HS first and then try to put them together slowly.
when i was working on the Coda, i used the metronome, starting from a very slow tempo and then gradually worked my way up. i know it is quite unmusical practising with a metronome but it really helps you to control your hands. the Coda, starting from Presto confuoco, is divided into a few sections: b.208--215 requires accurate landing of both hands and attention on the weak beat accent; the pedal here goes up,down,up,down and must be in coherence with the left hand so the staccato in the left hand can sound. for this section i strongly recommend the use of metronome because some people tend to go really fast after they're learned it well and musically the accent and fz are lost. b.216--237 is the section i personally had(still have if i don't practise it everyday) a lot of trouble on. this requires a bit of stretch in the right hand but if you have hands big enough, you may find it easier. the low notes in the left hands, which form the foundations of the chords being implied are very important - you may want to bring them out, especially at b.220 and 221 with the rising scale pattern. the right hand, as Chopin himself indicated, does have a few notes which shape out the melody. look for the notes with accents and also look for the quarter notes for they make up a melody which is intended to be brought out in the performance. although seemingly a technically demanding, "show-off" kind of passage, it still has its own beauty within. you can even just play these melody notes alone for a few times to let the ear know what you are bringing out when everything is put together. from b.237 and so on, there is really not much difficulty as long as you practise slowly. the fast runs and scales on the last page are really nothing compared to the previous 2 sections. focus on the the 2nd&3rd last pages of the piece and once you've mastered them, you'll have no trouble with pg 15.
overall, besides using the metronome and practising slowly, i also suggest that you practise each section in different rhythmic patterns: 8th to 8th is what Chopin wrote but you can try dotted-8th to 16th this kind of rhythimc patter and vise vesa (please tell me if i'm confusing you, i don't really know how to explain this. use dotted-rhythem)
i hope this is helpful. ahh also your post just reminded me that i need to pick up that Coda now and start practising it. good luck and please get back to me if you find this useful.