It sounds like you probably would benefit from a sinus CT scan and visiting an ENT. The septum alone is usually not cause of sinus problems, but it can contribute somewhat. Keep the nose moist with nasal saline like you're doing, and look for water-based ointment at the pharmacy such as aquaphor. Put this on a q-tip and rub it up inside your nose twice a day until the inside of your nose heals.

The soreness and crusting may be due to nasal vestibulitis. This is typically treated with an antibiotic ointment such as mupirocin. See your local ent for management.

See an ENT physician. In the meantime use a saline gel like nadogel in each nostril. Also try Ayr gel spray and put humidifier by your bed at might. Good luck!

It's possible that on the side you have narrowing and infection may have developed causing the soreness. By taking a culture from that side of the nose, it can help determine if you do have an infection. Have you ever had a nasal and sinus CT scan? That may point to a sinus problem as part of your nasal problem. A more complete evaluation would help determine the best course.