Here is a very interesting article from the Harvard Business Review: parents not using up their vacation time
If it makes you squirm a bit because the article seems to be describing you (like I felt while reading it) keep in mind that this could be a good thing.
The start of making changes in your life always occurs with the realization that there is room for improvement. I think this article will move you in that direction.
Let me also encourage you to take the time to evaluate your habits and consider some very practical small steps on how you can improve.
Enjoy this article, even though you too, might squirm a bit.