In order to build a muscle, you must break it down. In order to achieve extraordinary goals, you must cultivate discipline. Conquer yourself and nothing external can stop you.
There is a duality within us all, masculine/feminine. Understanding that males/females without a reference point for masculinity misintrepret it due to lack of an example. Submission isn't a bad word but she needs to trust your leadership in order to be comfortable being led. If you have proven you can lead and she still doesn't trust you, find someone who respects the traditional dynamic.
Dig deep and uncover what motivates you so that you can assure your goals become a reality.Are you motivated by pleasure or avoiding pain? How you can take success from other areas of life and apply them to any goals.
What activities do you do everyday that are keeping you in the proper mind-state for performance?
Why do you train? Why do you want to be fit? What will it do for you? Having a strong enough why will keep you from falling off.
Delving deep as to what drives you to do what you do is imperative to not giving up.