Hey ldssweetpea29, I know that your heart must be aching so much right now! I've found that there are many people here who can provide a great source of strength and support. I sympathize with you and hope my comments can help :)
First thing, know that YOU are a daughter of our Heavenly Father who loves you so very much! There are things that can be improved in every marraige, but what your husband did was a choice of his own, so don't blame yourself at all!!! Selfishness is at the heart of your husbands actions. You are so precious in the sight of our HF! Your husband is loved just as much by Him! My wife and I have come to learn that the true healing we need comes from the the Atonement of our Savior. It is powerful, and it is so very real. Turn your heart completely to the Savior. Also, find a trusted relative or friend with whom you can feel comfortable talking to. I know it can be a very sensitive and private matter, but your husband must understand that you need to confide in someone else for strength and support.
Also, are you working with your Bishop? Has your husband asked for your forgivenss, and are you both willing to work together for an eternal marraige? You don't necessarily have to answer these here, but a Bishop and LDS Family services can be of immense help and support at a time like this. My wife and I have began to improve our communication and showing love for one another, learning to rebuild what has been destroyed with the help of our Bishop and LDS Family services. It is by far the hardest thing we've ever had to do, but to me it is worth every step of the way. My heart and prayers go out to you. You are not alone in this!