This same incident happened to me twice. I learned that everyone loses one way or another. It's just whether people learn from their loss or not. Now on, I clearly state to the landlord that the security deposit will be returned if no damages are present, and explain my past experiences with other landlords. That is really all you can do and move on with your life. Remember, what you believe is going to become true. If you believe you are a push-over, then you are a push over. But if you change this experience into a positive learning experience, you will probably feel a little better.