I can't help but agree with franknbeans on this one. You should not have been in her house without permission, open door policy or not. That is especially true if you know she doesn't like you in the first place. You say she accuses you of things you don't do or make a bigger deal than necessary of the things you do. What if she had accused you of stealing or something of that nature? You could be in big trouble right now.
Something else I have to bring up. I have a 15 year old daughter. Her idea of clean does not match mine. When she cleans up her muddy boot prints or anything else for that matter....well, she tries, but it isn't cleaned as well as if I had done it myself.
Before you act hastily, I'd ask you to consider a few things. For one, there will always be people you don't like or that don't like you at every barn. If you like and get along with everyone else, well there are worse situations to be in. Trust me when I say there are far worse situations to be in. If you really like your trainer and are learning a lot....you may not find that in your next barn. Every public boarding barn has problems. Some worse than others. You can run into some real crazies. I board my horse, so I know this all far to well. Just some things to consider.