The hurt and anger will get better. It can takes weeks. Right now you probably don't even know how to put one foot in front of the other, right? Keep busy. Don't obsess. You can't change what happened so let it go. If you need to vent, come here and vent away!
It takes time to rebuild the relationship and probably even longer to rebuild trust. If he is willing to rebuild and so are you, you can do it. Just don't expect miracles over night. It will take months.
It is amazing how these spouses become pathological liars. Mine did the same thing. Even after I knew about the A. LWB is right, you gave him a LRT and it seemed to have worked. Way to go!
Don't worry about OW. I'm sure she is pizzed off. You can always block her number or change yours.