If you find yourself wanting to close down because you "followed your Heart" in the past and it didn't work out, remember this: each relationship in your life has been brought to you to teach you and to learn.
If you are seeking Love, you will manifest realtionships that show you your internal blocks to love. Celebrate past hurts because now you have the lessons in your hands and can learn from them.
To shut down is to miss the point. The goal is to remain open to love and become more intelligent about your choices.
Great love is knocking, it's your choice to open up.