Sexless Marriage Community Group
This group is for those people who find themselves married to a partner who has little or no interest in having a sexual relationship. This can be very painful for the other partner and leave them feeling rejected, unloved and unwanted. This is a group to provide support for this very painful and very private issue.

Before confronting her, I would make a decision. Come up with what you want, something constructive and positive. Ask her to let you speak your mind without interruption (OR write a letter to her which you read aloud to her) and then end it with "if you continue to refuse (request), I will do (consequence)." Give her an ultimatum.
Don't mention that you're thinking about an affair. If she really breaks you down, the most you should probably disclose is that you find other women treating their men right and you're wondering wtf you did wrong. You mention the idea of an affair and she'll either not take you seriously or be irate that you'd mention an affair.
Best wishes, dm6
I have come to realize most of us on here have a partner who is on the other end of the scope with no want or need for sex. I am wondering , as DM6 said, if you ask her just for a few minutes explain how you are feeling... maybe that would help. Often we get so wrapped up in building resentment from being disregarded or ignored. Really it is a matter of taking time to communicate how we are feeling (without pointing blame toward them).
We can only hope if they could understand what it does to us or how it feels to have them (for whatever reason) not want to touch or be touched by us . They have no clue just what damage that does not just to our marriage, but our self esteem as well. Good luck.
Don’t let this fester or it will grow into resentment. I let the sex problem in our marriage fester a long time and iall the resentment came out in a nasty argument I’m still ashamed of. We went to counseling after that.
In my case it's no sex and no marital bed. My theory is that if she really analysed this and the way she has handled it , it would be to some extent indefeseable. So better not to go there. It's better for her in the moment but it's destroying me and I think her as well to not deal with and fix it.