Following your heart is like driving on a dark, unknown road... You only need to see the next few feet! Not the whole map!
Do you have your life all mapped out? Are all your goals set, your five year plan, your ten year plan? Do you know exactly where you're going, when and how? Are you running, striving and achieving to the best of your ability?
Then you are just like a large section of the populace. In business it is often stressed that you create a blueprint for your future and have all your affairs in order. This gives you something to strive for and keeps you 'hungry.' This also creates a mammoth amount of stress.
You can't control everything, especially the future, it hasn't arrived yet.
You can take care of yourself, but trying to control things will never work. All you have is today, tomorrow may never come. You can't see into the future, therefore, put your best foot forward today, do what you can with what you have, and enjoy your life.
Consider this: you are today what you believed about yourself yesterday, and you will be tomorrow what you believe about yourself right now!