I agree divorce was the hardest thing to do. I never wanted to divorce my AD but when my friends told me it was not because I did not love him anymore it was because I loved myself more.
My AD also was living with someone else, I was alway so pissed at how he could of treated me that way, but how could he treat the kids that way. I am kind of still angry with him for that, he still does not know what to say to them. I have been divorced for 5 years now. It does get easier.
Just keep reminding yourself that you deserve better and that you are worth more. YOu have to start thinking what is best for you. The guilt will take awhile to get deal with.
But you only can change yourself no one else.