It is common for a married couple to experience bedroom boredom after a few years of marriage. In your case, you mention that the spark was non-existent from the beginning, and probably sex was an obligation, rather than a pleasure.
You are clear that things were different during your premarital sex life, and simply, as you say, you and hubby did not click sexually.
Probably he is passive sexually and many men are. Men are interested in sex, even the passive ones, more than women are. And these men have to be provoked to have sex. My hubby is passive, and with his passivity, if I leave it up to him, he would bed me, once or at most twice or three times a week. I want sex daily, so I provoke him, verbally and physically to get the sex I want.
How was he before you met? His previous relationships. What does excite him sexually? Did you ever discuss your likes and dislikes sexually? Fantasies? Does he masturbate? Do you? Before and now? Have you ever tried to provoke him sexually? Many women have the attitude and believe that "he has to start it."
A therapist would have certainly helped, especially that you were attracted to him, and certainly loved him, and assuming that he loved you and had no physical constraints.
You are still young, and in your "sexual prime," and it is not too late to bring a spark in your life. I am sure if you both love one another, and if you understand each other, you can be guided to rejuvenate your relationship with him, sexual in particular.