Has anyone ever been in a sex-less marriage?

I haven’t had sex with my wife for almost two years now. I have tried everything I can think of, to no avail. I have asked her, on multiple occasions, what else I can do to make her more attracted to me. Her response is always “Do everything right like you’re doing, I love you and you’re good looking…. I just don’t feel like having sex” even after trying to initiate. I’m in my mid 30’s, in shape and pretty much good looking. I’ve even had other women hit on me and compliment on my looks. But my wife still isn’t attracted to me? I’ve tried giving her a lot of attention; buying her flowers, spending quality time with her, trying different approaches in the bedroom. Nothing. I feel like I’m losing my manhood because of this. I have no desire to have sex with anyone except her, just because that’s the kind of guy I am. Any advice would be great.