What should I do about the scar on my nose after rhinoplasty? (photos)

Thank you for providing photos along with your question. Unfortunately, it’s impossible to determine why you still have a scar on your nose from these photos alone. One theory is that you have thick skin on your nose that may be interfering with the 5-FU injections. If that’s the case, then reducing the frequency of these treatments may help. However, I strongly recommend visiting a board-certified facial plastic surgeon for a consultation before you do. Your surgeon will perform a comprehensive facial evaluation to pinpoint the cause of this scar.

Without a physical exam, it's difficult to tell from the limited photos what is really going on with your nose. If there's thick skin in the tip of the nose, considered taping and steroid shots with 5-FU on a monthly basis until the swelling has subsided. If the Area that swollen is residual cartilage, then a revision rhinoplasty is going to be required.