“Recently I found that my husband of over 10 years was responding to personal ads on a dating website. He stated that he had not acted on the email, but I just can't seem to get past it. His
reason for responding to the ads was because of the lack of attention. Being a full time mother and homemaker being intimate at the end of the day is the last thing on my mind. I want to be in love with him again, I just feel like I can't get that back.”
In cognitive therapy there is a concept of thinking, feelings and behaviors being connected. The first paragraph explains your thinking. Your husband betrayed your trust and triggered one of your "biggest insecurities and fears." The second paragraph describes your feeling. You are having difficulties getting passed the pain you feel and your love has changed.
The part that is missing from your question is the behavior. That is a much harder question and one that I am sure you are struggling with. I feel you need to decide what you ultimately want from your marriage. If you want to make it work you need to attempt to open the lines of communication with your husband communicating what you are needing physically or emotionally. The same can be said for your husband. If he is not getting what he needs physically or emotionally from you, he should be communicating that to you rather than dealing with it by answering adds on a dating website.
Both you and your husband have unmet needs in your relationship that are being communicated. What is causing the breakdown is that those needs are being communicated through negative behaviors and feelings rather than being communicated effectively to each other.
Bottom line is that there is nothing more important to a good marriage than open, honest, effective communication. Without that relationships begin to break down and you ultimately end up with one or both partners feeling angry, betrayed or hurt.