That must have been a horribly difficult decision to make. I hope you are doing okay.
It's easy, being on this side of the screen and thinking/saying, "OMG, this poor guy, he should not have to put up with her lying, he should leave her!" And, while I personally would not tolerate the lying and cheating, and would make that same decision to end the relationship, I know it would be damnably hard to decide and do.
Take very good care of yourself in this difficult time. Though I think the choice you made is the right one, I do think it isn't going to be easy or fun. Make sure you have a good support network of friends or relatives you can lean on; if you don't, try to plan distractions for yourself.
I notice in your signature line you mention three daughters. If you're close with them, make sure they know it's not their fault and that they are loved. They may need some distractions planned, too, together as a family and also with just you and just Mom and maybe just on their own too.
Best wishes to you.