@neptuneblue,
Agree here - some people refer to this as "love language". Some may need words (I love you), some actions (like chores or cooking dinner), some time (where you put away electronics and go for a walk). (Your wife may feel everything is great and not even realize you are not happy or are getting the love language you need.
To her showing affection could simply be how committed you both are, that you provide and care for you children. She may not need a touch or hug and still feel loved.
I know you said you spoke with her but how? Have you ever sat down and said physical affection is important to me as it shows me how you care about me? That you actually need this?
You could have someone else's perspective; you can always go to a counselor to help you both work through this so both your feelings and needs are met.
If what you state here is completely true, on the surface and without actually meeting you both, it sounds more like you both have different needs and desires on showing your caring and love for each. If that is the case and you both are really committed to each other and willing to compromise and work on it, you should be able to meet each other's needs and improve on this. She may not just understand what you getting at. Sometimes it is harder for another person to fully understand or emphasize with someone else maybe having a counselor will help her understand your side.