I am so happy for you that you and your husband used this "ex-boyfriend" thing to spur you on towards bettering your relationship together.
From what I have read about your husband you are an extremely lucky woman. And a smart one...
Good for you, making a committment and sticking with it. This type of committment is a real "find" in a person, and the type that can do nothing but make the both of you stronger and more mature people. With that in mind, I am sure you can re-kindle the spark.
One piece of advice...forgive each other any hurts or indifference, and go back and do the things you did at first (when you first fell in love). Those are precious memories which can take you far in life.