I feel so sad after reading the last chapter, everything is falling apart. And through Kineta's post I realised that Nodame probably really is going back to Japan and giving up on her goal / Chiaki. And I don't know if Chiaki coming after her this time (which he will do, he loves her and he isn't himself without her) will do any good...
But I do also want to say that I don't think this is only Chiaki's fault. He realizes how important Nodame is for him, but being asked to marry her is a bit too much at that point. Furthermore Chiaki knows that performing with him is Nodame's only goal and he finds it stupid for her to quit after reaching only that goal and wants her to continue being great (that was somewhere in a chapter but I can't exactly find which one).