I agree with what your point is and I understand what you are saying, but you would have done much better for yourself if you made it VERY clear to her that you were going to have sex, and you would let her choose if it would be with HER or someone else...going behind her back is where you went wrong...and I don't mean "wrong" as in Morally Wrong...I mean it as in, WRONG for getting what you wanted out of your marriage/life.In the past I’ve heard reasons such as she’s tired with the kids, her job is draining, she’s put weight on and hates her stretch marks, she thinks she should see a doctor.
Like I said I’m a normal heterosexual man, if I’m having regular sex with my wife I’m happy. I know for fact I haven’t changed. Well beforehand I hadn’t anyway.
IF you want to stay married, you MUST explain clearly what you need and expect, and what will happen if you don't get that...and then work with your wife from there about what to do, including a marriage counselor if necessary.
THAT is your ONLY chance for success with getting your sexual needs met in your marriage.