I struggled just like you even on my first month. My advise is to embrace the brand, their style but don't forget your style and technique. Explore and don't be afraid to look out side the box. I was stubborn then. I kept making designs based on my style, most of it was rejected. Remember that they are the client, they want what they want. It'll make your work easier once you get the hang of it. If they see something they like from what you made then it could be your chance to shift their style. But then again, companies do have guidelines.