Mine are soooooo painful sometimes, it's horrible! In fact it's how I found out I was pregnant, I googled "sharp nipple pains" and all that came up was pregnant, pregnancy, pregnant lol! I felt a bit silly when I realised!!
To be honest nothing really helped until I went and bought some non underwired bras and was measured, my boobs were two sizes bigger and now ache much less in these bras. Also when it's unbearable massaging them helps!