Have you been making sustainable eating choices? If not, you're going to be disappointed in your results. Sure you can work out hard, but without supplying your muscles with lean protein for repair and growth, carbs for energy, and healthy dietary fats for proper function, they're not going to change. Trust me: Nutrition is absolutely essential.
You'll notice that your workouts will go much better when you're fueled properly. Having energy to do the work well will make a big difference in your body's response to training.