Puppy, it's NOT "right" for a person to do that to you.
But there IS a lot of gray area when it comes to relationships.
Because for one, there are levels of "betrayal". Before the Great Betrayal (your wife's adultery) in what ways might you have betrayed the fundamental trust she had in you?
I don't ask that in order to try to get you to blame yourself for her cheating. That's not your fault. It IS her decision to do it and she has to carry the blame for that. However, so-called "little" betrayals had to have existed prior to her jumping headlong into adultery. There had to be some. And they, over time, did their damage, opening her up to an adulterous relationship. When you TRULY accept your role in where your marriage is at today, you will see that this is not a system of points, where she got more demerits because her indiscretion was WORSE. They are ALL bad. ALL of our failures in ALL of our relationships are ALL bad and they added up to what brought us here. No one got here by their spouse's hand alone. We ALL helped steer our respective "ships" into the rocks.
You do not have to be her friend right now. You don't even HAVE to formulate a plan to be her friend LATER. But to hang onto the bitterness - though justified - only hurts you. I know you know this is true.
Change your perception and everything else will follow suit but FIRST you have to have a clear picture of your marriage - to include your role in it's apparent failure.