The OP's notation seems to be based on what was in the first edition, which apparently has a couple of typos in that bar - the Ab whole note is in a strange place, and the top C at the start of the bar doesn't have a dot.

Most later editions have rewritten this with the bottom C as a whole note:



It has always been a challenge for engravers to lay out keyboard music of this complexity so it is "easy to read", and different publishers often come up with different solutions. Also note the variety of "creative interpretations" added to Chopin's simple directions of "pp" and "Poco rall"!
IMSLP is a great resource for comparing different editions of standard works like this - unless you are required to use a specified edition for an exam or a competition, look at everything available and make up your own mind how you want to play the piece.