Welcome to Pherotalk Grizz!
Your girlfriend is so gonna kill you for writing that you need better sex. We are glad we met you and we are sorry you are gonna be taken from us so soon little buddy. 
The recommendations for pheromones are great but there is definitely something you need to do besides mones to get that sexual animal side out of her.
There was an interesting post in the lounge recently that I think you should read. Many times we love our guys but they take a back sit to romance and expect us to lead and that does not get our blood boiling. You said you are the leader type but are you that way in bed.
Try these products and being more open to try freaky stuff with your girl and tell us how it goes.
Your GC is on it’s way!