Most Helpful Guy
Start by deleting him from your accounts and your life! Too many people fall into the cycle, soon he may come around apologise profusely, and start the cycle all over again, remember that is ALL it is a cycle, it is not real and it is up to you to break it.
I recently broke up with someone similar to this, and I guess some of the best advice came from my dad. He said be thankful you found out about it now, rather than in a few years after you were married and had kids. He was absolutely right!
Also, don't assume that every guy who may seem too good to be true is going to be like this. There are many of us ACTUAL nice guys out there, its just the sociopaths imitate us at first to lure you in. Find an actual nice guy, you won't regret it ;)
Most Helpful Girl
The articles helped me so much. There is also a forum I joined on the site that helped. I went through the same thing, It basically destroyed me.
I am so sorry this happened to you. It was not your fault. Please check out the site.
Here is a particularly helpful article