HiCustomer Thank you for asking your question on JustAnswer.
Pretty much all you can do now is to tell him how you feel and what you expected out of the relationship. He may be afraid to be hurt again and therefore has put up a wall and doesn't want to let anyone in because of his wife's indiscretion. He can not expect to have a healthy relationship if he is living in the past. He may need some time to heal from what his wife did and may not have given himself time to find closure and heal. When a love seems to be one sided we find ourselves losing ourselves into trying to make the other person love us back that we tend to lose ourselves in them and I think that is what happened to your boyfriend and also what you are now doing to try to keep him and that is something you don't want to do. Give him time to figure out what he wants and if it were meant to be he will come back to you or stay with you. Would you rather to have him from his own will instead of feeling obligated or pressured to stay.
Just talk to him about the way you feel for him, tell him you are willing to give him time if that is truly the way you feel. Just be honest.
Thank you again for trusting us with your problem.
Yes you should tell him exactly how you feel and tell him that you are willing to wait for him if that is what he needs. I really don't think it is you and I know that saying "It's not you it's me" but in this instance I really think he has unresolved issues that he needs to work through.