Thanks for writing to Just Answer.
You may not like this answer, but yes, I think you are over reacting.
There is togetherness, and then there is too much togetherness that turns controlling.
Her body is her own. A person has a right to touch her own body whenever she wants. Needing to relax means she was feeling tense. Needing to relax is different than wanting to have sex, for a female. To equate this to having an affair is not reasonable.
You mention that your wife has chronic fatigue syndrome, yet you also say that you are constantly asking her for sex. Sex is a strenuous activity.
You may be in danger of taking the joy out of sex for her. When sex becomes something that is constantly in the forefront, asked for, and a major focus, women often feel that they have become an object to be used to fulfill the man's need.
Asking for sex is not a good way to get a woman in the mood. Women need emotional closeness in order to get turned on. While men often use/want/sex to feel close, women need to feel close first, and then sex comes to mind.
Please take a look inside yourself and see if there is any other need that is not being fulfilled in your life that is causing this intense focus on sex. Are you feeling like she is pulling away emotionally?
I suggest you spend some time with your wife really talking about what is going on. Keep sex out of the conversation. Show a real interest in her life, her dreams for the future, etc. Give her a shoulder rub, and don't turn it into a request for sex. Just touch and enjoy each other with no pressure to perform.
If you are using sex as a way to stay close to your wife, I'm afraid you are putting the cart before the horse, so to speak. Build emotional intimacy, and the physical intimacy will follow. There is a book that has helped many people add both kinds of intimacy to their lives, and I recommend it: Passionate Marriage
I hope this has given you a different perspective on your problem, and that its been helpful. If so, please click ACCEPT.