Multiple possibilities, but here is one suspicion and some facts.

Assuming that you are the current wife in the story, for ease of writing:

Suspicion: The previous wives filed for divorce because he cheated on them. Unless they told you with their own mouths that they filed due to lack of sex, very high chance it was actually due to cheating.

Facts:

1. Your husband doesn't care about your basic needs.
2. Your husband doesn't care about your emotional health.
3. Your husband doesn't care about your physical health (STDs, anyone?)
4. Your husband doesn't respect you, and will betray you behind your back.

Some may argue that these are not facts, and from say a purely objective angle, I agree. But when it comes to relations with other people, people will teach you about themselves through their choices and actions. Period.

But you give the impression that you might be the codependent type, feeling like it's your mission to figure him out and fix him. But the reality is that you are not his parent, not his doctor, not his therapist. You are his wife.

It is his responsibility to figure out his own problems, including getting professional help if needed. It is his responsibility to have respect, empathy and integrity.

Your responsibility is to decide if you think it's okay to dedicate so much of your life, energy and love to someone who doesn't respect you and doesn't care about you. That is where your thoughts ought to be right now, in terms of what is healthy.