Your hair is growing, but are you retaining that length? If not, here are a few things to try:
#1. Wet or wash your hair more often. Water's your best hair growth tool. Wetting it won't make it dry (quite the opposite), but a harsh cleanser will...
#2. Check your shampoo label for the following two ingredients: "sodium laureth sulfate" or "ammonium laureth sulfate". If you see either one and your hair is dry/breaking/not retaining length, then stop using that shampoo. It's too drying. Egg Tresemme products are good ;) shampoo & conditioner. I'm currently using the shampoo :)