Man, you seem pretty mindfucked and you're backing yourself in the corner. Did you considerr you immense dissatisfaction in your relationship, even if the source of it is private, is super obvious to your kids?

Your kids know that you're unhappy and feeling unloved and unattractive. No matter how confident and in control you think you seem, they're living in your house, they see the dynamic between their mother and you and now they think that's an acceptable relationship. The likelihood of one of your precious children ending up in, and staying in, an unhealthy relationship is increased by the fact that they have their strong, productive, confident dad allows himself to be brought into depression because he stays in a relationship where his wife cannot ever be attracted to him. You're being a terrible example to them.

Not to mention the fact that it's already been emotionally hurting you for years, and now that you've found out the reason it's crushed you so hard that you want to fucking castrate yourself. That's a ridiculously unhealthy mindset to be in.

If this was just a wife who didn't feel like having sex anymore, there are ways to fix that and stay monogamous. But it's not that. You are male and she is not sexually attracted to males. The idea of you trying to have sex with her at this point is gone now.

She doesn't think that her lack of interest in sex is going to change anything because she chose not to have sex when she married you, she knew going into this (whether or not she new she was gay) that she was not attracted to you and she did not enjoy sex with you, so she planned for your marriage to be as sexless as she could manage. She decided that for you. You never got the option. So she feels that nothing has changed, to her you were always going to be in a sexless marriage, the only difference is you know why.

So she chose a life without sex for both of you when you got married. You didn't get that choice. She took it from you, ignoring your high libido. And now you see the choice that was made and it's your turn to make a choice. You were unknowingly trapped in to a sexless marriage, yes a with a good friend, and a good mother, but a terrible wife, and a selfish person. And it's been hurting you, and she doesn't care. And in all likelihood your children know you're hurting and that it's your wife's fault even if they don't know why or how.

You feel cornered, because you're so deep in your mind you don't see your options. You have multiple. Stay an unhappy example to your children out of a false sense of duty. Tell your wife that she's not being fair and needs to open your relationship if you want to stay together. Or divorce, spend some time recovering, raise your children, and find a woman who wants you, though you may think it, it's not too late.