Is the affair over? If so why? Also, if you have no regrets and no relationship with your H, why are you still married?
If you are simply asking "Why I felt no guilt", I think the answer is fairly simple. You have completely emotionally detached from your husband and do not consider yourself truly married. You have the right to be treated with respect and feel wanted. you deserve to be happy. These are all powerful reasons to justify an affair.
You wouldn't be the first person to go down this road.