When people say you attract what you believe, it is even more than that. Your life totally centered on your beliefs... Sometimes, you unconsciously believe in certain things without knowing you do.
The reason your heart doubts certain things you want to consciously accept is because, deep in your your subconscious mind, you do not believe in those things.
Also, you should know that when there is a conflict of interest or beliefs between the conscious and subconscious mind, the subconscious mind always wins. This is responsible for why your faith fails you and Perhaps you think LOA does not work. You have to first reprogram your subconscious mind to work in harmony with your new beliefs before these things will start working for you.
Whatever you believe consciously and subconsciously are the things you attract to your life. Of course, you know it is not just beliefs alone. What you do, what you say, and how you do the things you do matters a lot. It is also true that what you believe determines what you do or say. In other words, what you believe is what you get.