First of all, do tell us what do you feel now: remorse, afraid of being found out, overridden by guilt...? Then you gotta tell if you two have kids, how old? What kind of financial situation you are in? If you can add the REASON why you come to cheat in the first place (SP), well second place (civies) too? How do you feel about your SO: love, hate...? Do you care if someone else hurts because of your "mistake"?
With all that info, hopefully with the power of colective minds on Terb(a hobbying world) someone MIGHT have an answer for you, then we all hope that you can find the right answer amongs the noice you have caused.
What i say is not making a joke on this thread nor on your post, but only you will know HOW it will end up for you, according to your own situation. Living and not able to cope with guilt is hard, being close to exposer is hard... it is really ONLY YOU KNOW.