Thankfully, my healing process was relatively fast for the most part -- the emotions had fizzled and pretty much died already, and I'd suspected for quite a while before I knew. I divorced him and went back to my hometown, where I'd been wanting to go for years. I started being able to just live for me and my son, something I hadn't had in a VERY long time. I took long walks, I ate good food, I lost a ton of weight, and spent time with people whose company I enjoyed. I stopped holding back my strong personality, and so found someone who fell in love with it instead of trying to discourage it. I still have stabs of insecurity, but they are getting less and less as I have learned to enjoy who I am...and the occasional person who sees the other woman and says, "He traded you in for THAT?!?!" kind of helps boost the ego a bit too :P.
I guess the biggest thing is to just change focus. What really helped me was to sit down and assess everything I wish I'd done or want to do in my life, and then start thinking about it as if there's nothing holding me back from them. The most important thing is not to dwell on the past, make the present what you want it to be, and make the future something to really look forward to.