In a battle, the best thing is to keep your trump card till the end. I don't want to sound like a professor, but the major problem in your team is that your moves are very predictable. That is why I decided to use a whole new strategy, and it worked fine with me.
Even if you used Earth Power, I had another Pokémon who could wall Earth Power and knock you out with Earthquake.
I still have a third team that I can battle you with.
I never stop creating steel teams.