The real reason or root reason why people stay in relationships that aren't healthy is because they don't value themselves, even love themselves enough. When you love and value yourself enough you will only give yourself the very best. To love and value yourself you must see yourself as you really are. Wonderful, divine, beautiful and amazing. Never in history has there been and never again will there be one exactly like you. You are rare and valuable. When we realize this, we will start making the best decisions for ourselves because we will learn to truly love and appreciate ourselves. It takes a while to reprogram our brains though from all the low level toxic negative experiences and things people have said and done to us. There are techniques though to speed the process like creative visualization and positive affirmations. Positive self talk can do wonders.