I think everyone who joins cx having worked before will be in the similar situation, unless this is there first job. You could consider this as a experience gainer and later in years move on to another airline.
I've know some people in UK, that has tried at least 3-4th attempt with vs and finally made it through, so I would say keep your head held high and don't let go. After all, as you said, that you're improving.
From what I was told, they are opening a Singapore base, because the HKG crew are struggling to provide the service that cx hopes to give in order to compete against Singapore airways.