What does it mean to “follow your heart”? It’s not about merely following your emotions. Nor is it about blunting your emotions in favor of pure reasoning. It’s about doing what’s most important to you. It’s about allowing your spirit to guide you, rather than following the path the world says you should take.
Follow your heart, but be honest with yourself about what that means. Emotions are involved, but they have to be balanced with rational thinking. The two need to work together. Emotions themselves aren’t irrational, but our response to them can be when we allow them to cloud our judgement.