Sometimes, no matter how deeply you care, some people will never see your worth. They ignore your feelings, overlook your efforts, and take your presence for granted. That's not your value decreasing, it's a sign you're giving your heart to the wrong people.
A persons actions can make it clear that they have no respect for you, regardless of what they say. Their actions clearly indicate that they don't value you. When you notice this, take it for what it is. Remember, actions always speak louder than words.