The first thing to consider is whether the situation is your fault. Ask her whether this situation is something that you caused, or whether there is something that you can do to influence her decision.
Beyond that, Shuddupandkissme has spoken. We shudder to think that brosen's advice may have to be acted upon. Why? Because communication is the number one problem in marriages. Communication takes time, commitment and sacrifice. The divorce rate reflects how many marriages fail to achieve it.
Nevertheless, many marriages do achieve communication and because of this there is reason for you to maintain hope.
Be prepared to make the time, commitment and sacrifice to gain more intimate lovemaking (not sex) with your wife. It has to be something that she looks forward to and not something that she endures once a month. Get it?!