Playing it too safe.
Everyone experiences unhappy times on occasion, but there is a big difference between experiencing a temporary bout of sadness and living a habitually unhappy life.
Don't play it so safe that you put yourself in situations where none of your potential options satisfy your calling. Dream your dream, but also realize that you are more than just the dreamer, you are the point of origin for your dream's reality.
Your dream is your creative vision for your future life. You must break out of your current comfort zone and become comfortable with the unfamiliar. Start smashing through those emotional barriers. Move forward. Life doesn't magically give you what you want in your mind; it gives you what you insist upon with your actions.