Sometimes practicing relaxation techniques works--some as simple as deep breathing--when you are in uncomfortable situations. The idea is that you can't feel relaxed and anxious at the same time. Another thing is to take small steps toward your goal of being more social. Another technique therapists use is to tell clients to "act as if"--or fake it 'til you make it. Even though you feel stupid or awkward and weird, act as if you are smart, poised, confident and interesting. Which, by the way, you probably were (and still are) in your past life--the one, you know, before lying and cheating poisoned it.
I think nearly everyone who has been in our situation, no matter, how accomplished, beautiful, socially skilled or successful they are, are knocked completely off-kilter by experiencing a betrayal like this. You just have to eliminate or reduce the negative self-talk (I'm worthless, I don't have anything to say, I'm out of the loop of current events, I can't trust anyone) and replace it with--"I have experienced an awful thing and I've survived, I have an awesome son who is going to grow up to be a wonderful young man, I'm beautiful, inside and out and people are lucky to know me."
Being shy isn't a bad thing, sometimes I get so tired of those people who are all up in everyone's face, sucking all the air out of the room, that a more thoughtful, quiet person is refreshing. Just put yourself in as many social situations as you can and ask LOTS of questions. Most people are so willing to talk about themselves and their opinions and activities you might not have to say much of anything but, "really?" or "wow, that's so cool!"
As far as current events--read a People Magazine and Time or just take a swing through Yahoo or MSNBC and you'll have everything you need to know for a conversation.
The best thing you can do is just smile and be approachable. See every person you meet as an opportunity to make a new friend. You don't need to trust people with your deepest secrets or personal information to be friends. When they earn your trust, and they will, if you let them, you'll know. Trust your gut and tell yourself everyday that you are AWESOME. You are and eventually you will believe it.
Oh--and go easy on yourself. Be your own best friend. One day at a time--it WILL get better.