I'm sorry that your wife is withholding so much affection from you - physically and emotionally. That's wrong of her. At the same time... would you really enjoy the sex knowing that she has zero desire to take part? How did you end up married if you are so incompatable with each other with intimacy??

Cheating is wrong though. But if you tell her that you are upset that none of your needs are being met (and they're perfectly reasonable needs!) and that you are starting to question the relationship, and that something needs to change..... you can bring up having an open marriage as an option. If she doesn't like the idea of that at all, then ask her how you can both find a happy medium. It really isn't fair of her to ignore your needs so severely. Like... an open marriage doesn't mean that you'd have another relationship with someone... it could easily just be random hook ups. I'd point out to her that you seem to be considering that as a way to actually save your marriage.