Are you still using the warm water wash? I found that it helped even when I no longer needed to wash the area. The warm water just felt good.
I never tried a Sitz bath, but I have heard it helps.
My hospital also gave me Tucks-like pads and an antiseptic spray. The spray helped to numb the area. Do you have any of those?
It's been a while (DS is 6 and DD was a c-section), so I don't remember how long I was sore. Fifteen days does not sound too long to me, though, if you have stitches that need to heal.
DS '04 "Boogaboo"
DD '08 "Lilybear"