Since I don't know the true story around about why you consider she does not love you anymore (e.g. you know for SURE that she is with another person or found an email about that situation, etc etc) I will be conservative, sorry is that bothers you but I have found in several relations that even something like "I won't have a child" means to somebody that means the spouse does not love the other...which can be argueable. Now you don't have to tell me your personal situation...just a thought.
Now, why to prolongue the agony? Is that good for you? I don't think so. Let it be. If you are sure that she does not love you anymore and show it with actions and words...then I guess is better if you move on. Hurt but that's life. Wouldn't be better now than later with more financial, emotional investments done? Think about it.
With a divorce, now or later, she still can apply for the removal of the conditions by herself. And to have a divorce after a year of marriage (that is almost normally after the permanent residency is granted) does not mean that is look "obvious" that she married you for the green card, will all depends on the proof that she can show. And will be in her, not yours. Will be in her to demostrate that she did not marry you to avoid the immigration laws. And believe me, does not matter how are the family laws in the state you are...nobody can continue marry with a person that does not want. If there is nothing to fight for e.g. financial obligations in both names, children...then even she can file for divorce (and she has two years to spare) and even if you want to contest, a judge won't get that much fuzz if there is nothing in between like children. Unless in the state you are, a two year separation is needed or other major requierements.
So again, think about it. It's true, you are hurt and that's normal...but now instead to think about what she might do or what she did or what she does...start thinking about you, what you want and what you going to do for your own health.