I know a lot of other people have already commented and cleared things up for you, but I thought I'd chime in with my 2 cents and what really made it click for me. I'm a cis-female lesbian. Born a woman, happily so, completely comfortable in my skin and my body. But I love women. I have absolutely ZERO desire to be a man. I do perform in drag for fun, but that's just putting on a costume and assuming a character. I love my girl clothes and doing my hair and makeup and wearing dresses and high heels. But I'm completely attracted to women, femininity, curvy bodies, breasts, and I LOVE having sex with women. So, when an ex of mine confided in me that she had at one point considered transitioning and still had some residual dysphoria about her body, I had a really hard time understanding it. A few years later, I met a lovely trans woman who I'm still good friends with. She explained to me how she felt when she was growing up. She struggled for years to understand her identity. She never felt comfortable in her skin, always felt like she didn't belong in her body, was very uncomfortable with all of it. When she started experimenting with wearing women's underwear under her clothes, and eventually into dressing in women's clothes all together, she started putting pieces together. She thought she might be a cross dresser so she started talking to some cross dressing males and came to realize, no, it wasn't a fetish or sexual activity for her, so then she thought she might be gay. She started socializing with some gay men and exploring that a little bit and realized, no, she definitely isn't attracted to men at all. Finally she stumbled across info on being trans* and things started to click. Eventually she began transitioning and is now fully transitioned. Her gender identity had nothing to do with what she was attracted to. What finally clicked for me, listening to her story, was "what if I had been born in a male body?!" I love being a girl, love my body, my breasts, my hips, all the things about being a girl that I enjoy. What if I'd been born fully myself, all my thoughts, my brain, my preferences, my desires, ME, but in a different body? How miserable would I have been if I'd had no breasts and a hairy chest and facial hair and wearing boys clothes everyday. Sure. I'd be "straight" because I'm still me and still attracted to women. But I'd have been so unhappy in that body. When I told my friend this, she said that's EXACTLY how she feels. Before talking to her, I'd always thought, gosh, there's no way I'd ever want to change anything about me. I'd never want to change my body to be a man. But I was looking at it from the wrong perspective! Because I'm female-bodied AND female-identified, of course I'd never want to be a man so the idea of changing into one was completely foreign and horrible to me, but what if I'd been given that body at birth! If that had happened to me, of course I'd have wanted to change my body because I'm female to my very core and for the same reason I'd never want to change into a man, if I'd been born as one I'd have been desperate to correct that! But even once I did, I'd still have been attracted to girls.
So, according to your profile, you're a straight and happily married female, and I'm assuming that you're happy and comfortable with your birth assigned gender. What if you had been born in a man's body? Still you in every way emotionally, intellectually, with all your preferences and desires and attractions, everything about you still being you, except you have a man's body and a penis. You'd still like men, still want all the same things sexually that you enjoy now, but just have the wrong body. Assuming you're like me and happy to be a woman, you'd probably be just as miserable in a man's body as I would be. Thinking this way suddenly made everything much easier to understand for me. Not sure if it will help you but hopefully you find this as clarifying as I did.