I read your post and two things immediately come up for me. Your having "the talk" with your wife sounds
1) All about you and your needs/wants but not about her and her needs/wants. The fact it does not work has not seemed to motivate you to change you just keep hammering at it. Clearly it is not working and that's on you.
2) That you directly tie your sense of confidence and well being to sex essentially tells me you see your wife as an object. What she hears then is that you basically just want to masturbate into her because that makes you feel good. Basically you do not want to be intimate with your wife, you want to be satisfied by her.
This is I suspect the core reason why your wife is not turned on by you. I see this over and over and over. Men become embittered and start hating their wives but do not take responsibility for how they generate the energy that creates the cold dead bedroom syndrome.
No one wants to fuck a manbaby. I know it sound harsh but your problem is not your wife not wanting sex with you. Your problem is that you do not take responsibility for our own happiness, you do not take care of yourself, and you are essentially asking your wife to be you mother and take care of your needs rather than engage in a partnership. She';s already a mother. She did not marry you to take care of your inner child, she married you to be with a man, a leader for the family. You are not acting like a man or a leader of your family.
Just becase you are having "the talk" does not mean you are acting like an adult. Being in a man's body and using grownup words does not mean you are a grownup. Everything about your post suggests to me that you are not behaving like an adult.
So many couples get confused by the roles they play in marriage and parenthood as their identities and that being able to play these roles mean they are adults. Being a working man is not who you are, it is the role you play to maintain a lifestyle. Your wife staying at home to raise the children is not her identity, it is the role she played to maintain your lifestyle. Children can play out roles they do not understand, the same goes for adults who emotionally and spiritually not grownups. Just because you play and perform the role of grownup does not mean you ARE a grownup.
It sounds to me you need a radical look at yourself. So I would suggest you go into counselling yourself to get your house in order. I would also encourage you to read the works of David Dieda and read a book called "The Way of the Superior Man". this is his website. http://deida.info/
Until you start acting like a leader and acting like a grown man then it is not reasonable for you to expect sex from your wife. The very fact you expect it is a killer. You need to grow up and I don't mean that harshly but I mean it honestly and faithfully. If you grow up you will become attractive to your wife again and she will be begging you to be intimate with her. You must radically change you views on sex, gender, intimacy and masculinity.
Some people in the thread are full of rage and misogyny. Feeling hate toward your wife and telling you to hate your wife. I find those types of comments sad because those are people who have given up on being grownups and are permanently entrenched in being angry two year old manbaby's throwing their toys out of the pram and having mantrums. You are sliding into that territory and likely already have one foot in it. It's not too late for you. I would again recommend David Deida's work. He is in my opinion the best man out there for men who really want to be masculine, not men who want to insulate themselves from taking responsibility and hiding behind misogyny and woman hating.
Good luck. I do hope you find a path that leads to intimacy and further alienation from yourself and your life.