Welcome to PsychCentral, Daisy1916.

Everybody does things in life that we regret, and it sounds like you are feeling extremely guilty over what you have done. The good news is that you realize that you've done something wrong; I think it is far worse to go through life doing horrible things with no remorse.

Do you have a reason why you had the affair? If so, I think it would be a good idea to talk it through with your therapist. I wish you the best.