It could take anywhere from 3 to 6 months (depending on how its, healing and how much you irritate it) befor it stops being so sensitive. Google "total pillow" and get something like that to lay on when you sleep. It will decrease the amount of irritation it gets while you sleep, and let you sleep eaiser. Cartilage piercings take a very long time before they stop being so pissed off.

Not a pro, but this is from personal experience.

Yeah I definitely love the way they look. I'm guessing it'll take longer since I got all six together. My tragus just weren't this sensitive.

Cartilage doesn't have it's own blood vessels, and relys on the surround tissue to give it what it needs. Also smaller sizes take longer for the healing process to kick in as when you get any mod, your body wants to push it out.

Things like your health, and daily abuse also prolong the healing. As Kerian said, cartilage depending on conditions can take well up to a year to fully heal.

However when it's healed it's a pretty solid mod, and should be problem free.