A good place to start is in the "Healing Library". Lots of good information there. What is your situation right now? Is your WS remorseful? Is he NC with the OW?
I am so sorry you find yourself here, like you, we betrayed spouses were blindedsided by the person we put our faith and trust in.
I will echo the above posters that you should tell the other spouse. He has a right to know he is living a lie, and his must get tested for STDs (as should you).
This emotional roller coaster is extremely painful and exhausting, but you will get through it with time.
Your husband needs to go NC (no contact) with this woman immediately. No phone, emails, IMs, texts, nothing, nada. Totally transparent with all of his media, phone records, social media, etc. Accountability for his whereabouts at all times. Individual counseling to help him figure out what he was thinking and how he can fix this.
Counseling for you would also be a good idea.
Two books I highly recommend are Not Just Friends and How to Help Your Spouse Heal from an Affair.
Read the Healing Library. Chock full of information, and information is power.
Keep in mind that he owns his OWN actions. It has nothing to do with you, don't ever allow him to make excuses for his behavior.
Sorry you find yourself here. Please know that there are many kind people here that have lived through the horror that you are now experiencing.
They share their time and their stories in hopes that it can help others.
You have just been dealt the worst betrayal possible. The hurt and angst is indescribable to someone who has never experienced it.
Breathe for today. One day a time. It takes TIME. You are in shock and understandably so.
Please check out the Healing Library in the upper left hand corner. There is a lot of great information for you to read and absorb.
(((gently))) the OW's husband deserves to know. Wouldn't you want him to tell you if he had found out?
It is really new. Take it slow and post often.
We are here and we are rooting for you.
Good luck and God bless.
Best of luck, you are not alone.
Just brace yourself because cheaters always lie when they're first caught, and give you a very watered down version of the minimum truth. Unfortunately most of us were trickled-truthed as the months went on, and it's not fun.
Welcome to SI and please know you're not alone.
As you will read and see, everyone on here would prefer not to be in this situation, but we are. We all survive. It will feel sometimes like you just can't take it anymore. You can. You will. Know that we are all here for you.
Every minute, leads to every hour, which leads to every day, thus getting us to the next one. Just take care of yourself.
As a BH, my WW came clean to me with her A, but she was not going to had the OM's wife not found out. The OM's wife was going to tell me if my WW didn't. This is very common and you will see everywhere on this site. Do what you feel makes you comfortable, but also think about if you would want to be told if the OW's husband knew what happened.
Come here and come here often. You'll make it. You'll survive. You'll be resilient. You will recover.