What a great and important question! It can be really tempting to get the attention and connection you desire from a man when your husband has been working too much and feels unavailable to be there for you and your needs. There are many answers but they all depend upon your relationship needs and your personality. Just from your question, it is clear that you don't want to cheat on him, you just feel you have needs in a relationship and are unsure how else to get what you need.
This decision is so important that it can literally be the crossroads in your relationship that can end it or it can lead to new levels of closeness and intimacy with the person you already married! Here are two things you can do.
1. Open communication: You can tell him how you are truly feeling about the relationship, (eg that you are craving his attention, intimacy and to feel close with him), and tell him HOW (clear, practical ways) he can do a better job of this.
2. Whatever emotion you are craving from him leading you to consider cheating, ask yourself: "what is that emotion?" And, "aside from cheating on my husband, how else can I give myself that emotion?"
To navigate this fork in the road, it would be very helpful to have a session with a qualified, experienced Relationship Coach. As it happens, that is my specialty and I can share with you very, very briefly some ideas to get you started. You can imagine how it might be worthwhile to have a longer conversation about this. I wish you the best and hope this was helpful.