small nipples? breast feeding tips?

So my son is almost 2 weeks. After poor latching at the hospital. They are finally healed. I thought my nips were getting thicker but all of a sudden they look small!! One nipple when sucked on looks like lipstick shape after with line down middle.. and other boob nipple is round.. but I can't get them to stick out enough.. some days are better and some days they don't hurt.. any tips? Does nipple size matter?