Well, whether she is having an affair or not, what everyone is telling you to do would be the same right now.
Any kind of pursuing would feel "icky" to her. I used to hate the ol' victim/sad puppy dog look my H gave me. Everything ticked me off. Leave her alone and look within yourself to find what will make you a strong, confident, differentiated man. Be a man that any woman would die to be with, and a man that doesn't need a woman to be great. That is attractive. Don't think "what can I do to make her love me again" (ick), think "what can I do to be confident and happy", and then get ready to be patient.
