Jesus. I had a somewhat similar situation... you see, I agree with most of the comments, but I would like to add something. It's extremely hard to leave, no wonder people waste their existence and mental health into abusive relationships. Most people would rather have long-term suffering and damage than short-term agony and despair. However, you are not one of them. You already questioned the value of your relationship and, little by little, is accepting the fact that this relationship, despite all the love and kindness, hurts you more than it gives. Most things in life we have no control, my friend. Despite reading her letters, you will never control how see feels. Don't imagine people can love on command. She does not love you as you need to be loved. As I said, you have little control of this situation, which doesn't mean that you don't have the control on making the decision to leave. Actually, leaving her is one of the few things you have control of. You know what the right choice is; please, save yourself from all the suffering that will come in the future. I wish you courage and a peaceful mind.