I have a question to all you women, and hope you can help me with you perspective?

My wife of over 25 years workes nonstop because of her job, she is always willing and always has energy for them and kid stuff.  She has always been very conservative sexually.  She is in the early/mid stages of menopause. At the beginning of this year we where having sex 1 to 2 time a week, which I though she had finnaly awoke sexually, prior to that once every two weeks was a lot.  Then she decided to shave her self completely out of the blue, which I had asked her to in the past but she always rejected the idea.  In that period she now wanted me to perform oral sex on her which I did, partially in the hope that some day she would return the favor.  I found a book in her breif case on how to master oral sex on men, so several weeks later I asked her to return the favor that I had just proveded her.  She got really mad and refused, when I asked her about book she had no good answer.

She prides her self on having the best MILF body, in fact the last time we went to a wedding for her work, she work a tight dress with nonthing under it, she said that her bra and thong could be seen under the material.  That night she danced with many younger men, she would grind her self against their groins then rub herself up and down their erections.

Now several months later she is refusing to have sex with me at all, claiming that she is to tired. 

Am I right in assuming that she is having an sex with other men?  And the need for the book was do to the fact that most men would not be as understanding about oral sex as I was. I have asked her directly what is going on, but she always has a lot of excuses some good and pretty week.

She works 24/7 every day, she does bust her ass at what she does.

I'm tried of the lack of intimancy between us, I need to feel and hold her, but she resists.

What ever advice/insite you can will be greatly appreciated.