It gets to be more work than thrill, more trouble than it’s worth.
Don’t blame your husband for fading on you here. Most do, especially in a marriage situation. Marriage combined with BDSM is like expecting the magician’s helper to always be thrilled and amazed by the master’s illusions while at the same time expecting the master to come up with new tricks every night. That’s a difficult thing to keep going over the life of a marriage. This may be why the majority of both doms and subs are single: they need to be free to move on when the thrill fades.