Birna, you do need to talk with him further. I'm not sure how you are approaching the subject of him not being dominant now, but make sure to avoid blame. Use open ended non-blaming wording such as "I've noticed that you're not being dominant so often these days. How are you feeling about it?" If he gives a non-committal answer such as "I don't know", it's OK to tell him that you miss it or even that it's important to you.
If having discussion on this topic is proving impossible, then you might have to face that you've got communication issues. And communication issues don't bode well for marriage. If he can't communicate about this, then he may not communicate about other important issues which pop up.
You wonder if he's pulling away from you. Is he pulling away in other areas too? Or is the rest of your relationship highly satisfactory?
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.