DW here. You are not alone with the "I have to kiss her ass for an unspecified amount of time" feeling. DH told me he felt that way too, when sex was becoming less frequent post baby. While I didn't appreciate the phrasing (he said, just like you, "kissing your ass"), I understood the frustration he was feeling.
So, we scheduled a regular date night every week. Sometimes it's just a quickie and sometimes it's awesome, and sometimes we go for other nights, too. But we always keep our "date" with each other. It proves to him he is a priority to me and that sex is something worth making time for.
I also sympathize with your wife. It's hard to explain to guys, but women have different hormones at different times of their life and even at different times of the month. It can be a challenge to feel sexy and to feel like initiating something. But usually, once a woman gets started, she can rise to the occasion

So, if I were you, I would discuss having a date night and really focusing on your physical love the way she focuses on exercise/hobbies.
And, because I know it'll matter to her: When you bring it up, make it sound romantic, like: "I love how you find time for your other passions (gardening, exercise, etc) and I want to be one of your passions again. You are the one great passion of my life -- please make time for me once a week!"
If that doesn't do the trick (and she's have to be seriously anti-sex for it not to!), I agree that counseling is a good next step.