I have been looking into buying the DR book. What is the objective of the other book?
It's a relationship manual for Men. Helps you really evaluate how YOU can make a difference in your marriage and YOUR life and how you move forward. IMO it goes great with DR, but more customed to you.
Depending on your self esteem and confidence right now I also recommend:
No More Mr. Nice Guy and Ways of the Superior Man
You need to use this time to better yourself and focus on you so that you can be the best MAN and Husband you can be.