I understand what you're saying OP. I can tell you right off the bat that none of the people commenting and judging you are in a long term relationship, married, and with kids . These people are so self righteous and act as though physical attraction isn't the first thing that draws you to a partner. Personality, sense of humor etc.. These things obviously matter and are huge in attraction, but 99% of relationships are born because you like what you see, this is science and you can't help the way you feel. Additionally, these people more than likely have no experience with being in a marriage with someone who has completely given up and changed the way they look. It sounds shallow, but there is nothing more unattractive than watching your significant other no longer care about their health and appearance etc.. If anything, that serves as the foundation to find other imperfections in them, and thus fall out of love. You see this all the time with people in the military who expect to see the same person that they left 1 yr prior but find a much different person. It's sad, and sounds awful, but these other people do not understand because they've never experienced anything like this. Like you, I'm married and recently became a father. I'm 30 and have been with my SO for 10yrs. We've had our rough patches but I can't tell you with certainty what exactly got us through it. It was similar in that we both acknowledged that something was wrong in our relationship but at this point it was too complicated to just walk out because our lives were so intertwined. We were able to muscle through that period of time, travel together, share our accomplishments and failures together, and from that here we are several years later with a baby and a fully blossomed relationship.
Anyways, I'll offer you some pieces of advice that you can consider or ignore that might reset your head:
1) For a week straight, be OVERLY affectionate . Laugh at her jokes, get her flowers, take her to dinner, make love to her every night like the first time etc.. You'll have to force it on your end of course, but given that she knows how you feel, this sudden change might spark something in her that may help you too. It might motivate her to want to look the way she did 3 yrs ago, it might make her want to find more things in common with you. It might make you find something about yourself that you can change too.
2) Sleep with someone else on a as needed basis. Don't get into a second relationship, don't give some girl your number and so forth. Just go to Vegas or whatever on a "business trip", sleep with some stripper who only wants your money, no strings attached. You obviously still care much about your wife, so never tell her about it but use the guilt as a catalyst when you come home to her . She won't know that you fucked up, but you will, and that guilt (or fear of her somehow finding out) just might make you see her in a new light. You'll realize that you have a second chance that not most guys get. It will either clarify exactly how you feel about her or it will do nothing.
3) if divorce is not an option, you could always try counseling . I'm mentioning counseling last because in my opinion you should stir the pot up a bit before completely opening up .
It's a pretty messy situation but there are dudes out there who understand how you feel. You're bold for putting your raw feelings out like that. But anywho, best of luck to you. You've got 2 pretty good reasons to keep on keeping on.