I'm going to give you my anecdotal, personal experience- take it for what it's worth.....
My husband and I have been together for 12 years. Married about half that, and we have a young child.
In the first 5 years or so, sex was infrequent, routine, boring. We started this way. Why I stayed, I don't know.
I'm a ridiculously high libido. No man I've been with has been able to keep up. Even if they wanted to, they physically couldn't. I'm kinky. I like fulfilling fantasies, I like my fantasies fulfilled. My friends in college called me a sexual revolutionary, because they'd never met another woman like me.
So after serious boyfriend number 2 (and 2 previous non serious highschool boyfriends).....I started my personal journey of nonmonogamy - I needed more than any one person could give me, physically and emotionally and mentally.
Am I an addict? Probably.
Does it matter anymore? Not one bit.
When I met my husband, I knew I wanted to settle down. He's a catch in all ways....except sexually, for me. But I love him. Love being with him.
(We've been nonmonogamous from the start....he has taken "advantage" of this once. And me twice. Both more recently.)
For 5 years, from the start.....it was a boring/dying bedroom. I'd communicate my needs and my desires on what and how I felt sexy and wanted. He wouldn't open up. He wouldn't react to my fantasies, negatively or positively. Intimacy was rare, sex was rarer. I started as a best friend and roommate, that one could occasionally fuck, and that was it.
I initiated. I was rejected. I attempted sexy things....from the romantic (candles and music and rose petals) to blatent and kinky (lingerie, mild bdsm, etc) because I didn't know what turned him on....and he rejected me.
I was rejected over and over, and when we had our generally "scheduled" sex, it was impassioned, simple, boring.
At the end of 5 years, after many tears, arguments, etc....he opened up. He told me a fantasy. I immediately set to fulfill it. I didn't overbear it. I was ready to try when he was. I did it, and it was the best sex I've ever had. It's an uncommon occasion, but we still bust it out on occasion, when he's ready.
Now....he wants sex more. He initates more. He rejects less.
Here's the kicker....the years of feelings of unsexiness, the years of rejection, the years of being unwanted.....they have left me unable to trust that he truly wants me. That I honestly turn him on. That I'm not more than a need fulfilment.
I've become what I most dreaded since finding my sexuality....a low/no libido woman.
I am currently at a bar. I've left him.....as of 30 minutes ago. We don't know how we're going to do this with the child. But I'm sitting at a bar. Alone. In tears. Knowing that the man I've loved more than anything, somehow, will never love me the way I love him. (Note - we've done the quizzes, the self help books, the counseling....you name it.)(note 2 - I'm across the street from a hotel, so I'm good. No driving.)
I can never believe that he loves and wants me the way I need and want him to love and want me. And it grew worse and worse because it bled into everything.....leave a dish out? Not offer to change a diaper? Not mow the lawn when it was promised? Those grew resentment and overall dislike for each other.
Do yourself, and him, a favor.....do not marry. Do not have kids. Do not continue this relationship unless you fix this problem.
It will destroy your soul.