You can file for divorce without any reason in most states these days. I had that kind of marriage too, but most States are no-fault now, so it doesn't matter what happened, you can just file. You should sit down with a lawyer and discuss your options.
Sadly, the loss of intimacy is a factor related to both spouses, not just one. No one should consider divorce without both parties going to counseling. Marriage takes work and many people are selfish and self focused, which doesn't leave much room for another person. There are many factors to this issue, and pornography is usually the #1 cause. If you do not have and show respect to your husband, that can cause a him to feel inadequate. It's rarely a one sided issue. If you truly love your husband, you will make the effort to seek counseling and find out what it is that you can do to help your marriage. Marriage is about being "selfless."
No, don't get a divorce because of sex. Sex is a wonderful part of marriage, but it shouldn't keep it together or not. Yes, I will say that your husband is being incredibly selfish for not having sex with his wife, but that is no good reason to file for a divorce. If he really loves you, he could never let you be that unhappy and just ignore your feelings. Something is definitely wrong and you have to find out what that is. You can't just ask him for sex, you have to ask him why he won't have it. You also have to warn him that it is causing you to have a problem with the marriage, because it's affecting the life he's giving you now. If you love him, always show him how much and always expect it in return. Sex would then happen naturally, but because it isn't something is lacking and you have to find out what that is. Now I feel like a total shrink. :P
You can get divorced simply because you don't feel like being married anymore. Hell, you don't need any reasons. You may not even need a lawyer because I think I saw a "do-it-yourself" divorce kit somewhere or maybe it was some software I saw somewhere, I don't remember. (And I suppose some people still wonder at my bachelorhood.)
51% of marriages end in divorce. Do you really want to join them? It's like the words "'til death do us part" have no meaning anymore. So yes, you can file for divorce if this marriage means nothing to you. But before you do, ask yourself if you really do love your husband. Chances are, you do. This is your choice, but it would really be a shame for someone to give up on their marriage just because they're not getting any sex or attention. I suggest talking to your husband about this before you go ahead and ruin a perfectly good relationship.