Hon,
I am so sorry, you sound so sad. I know it is overwhelming right now. All you can do is get through today, not tomorrow or next week. Take one day at a time.
Yes, I would reach out to an attorney. As much as it hurts, he obviously has moved "on" in his life, if you can call it that. I know it is hard for you to grasp, but he gifted you this, by leaving. You joined here back in Nov. 2012. You have put up with more then I am sure people would comprehend, and oh boy I am sure you tried to Save the marriage.
I divorced my axh after 34 years together. It was gut wrenching and the most painful thing I have ever gone through, but I survived, and you will too. My life is so calm. I am in control. I am happy. I know you can't see it now, but you will be ok. You will have many very bad days, but those days will lesson in time.
Keep sticking around, posting, asking questions. There are many of us who have walked this painful path, and we can help, or just send you a virtual hug for support. We do care and we are all here for you, my friend.