Bryan, affairs are not about what you lack. It's not about not being blonde enough, ripped enough, tall enough, affectionate enough, or any of those things. Having relationships with other people has nothing to do with you. If I sleep with a woman, it isn't a male partner's fault for not having enough vaginas, if you can dig it.
I'm not a naturally affectionate person when it comes to romance, so I feel your pain. It's something you work at, piece by piece. You know how to love. I can see it in your writing. Is it analytical? Yup. Would it make a good romance novel? Nope.
A look, a note reminding you that you love her, or a simple touch on the small of her back are gentle reminders of the depth of your love. You don't have to be Elizabeth Barrett Browning; you just have to be straight-forward. And you may find open relationships trigger new ways to express your love, and be loved. It's opened avenues for me I would have never imagined, and it will get better. Keep fighting for your love.
“Edit yourself, bitch. Edit yourself.” – Chad Michaels