My stomach is in knots for you right now. Your pain pours off the screen.
I am so sorry you are suffering like this, but I want to assure you...it will get better. You will be OK perhaps just not for a very long time.
You have already taken the first step to healing, you reached out for support. You found a very safe place full of very compassionate people that know exactly what you're going through. We've all been where you are now and most of us have made it out the other side.
I hope you share the rest of your story.
I also hope your WH will start to come to his senses and will do the hard work and heavy lifting that is required to repair the immense damage he has done.
For now, please take good care of you.
The shock of infidelity can cause PTSD. It takes such a heavy toll on the betrayed. What you're feeling is normal, awful but normal. Sometimes it takes months to begin to process it all.
Do what you need to do to heal yourself. Be kind to you now. If you can go to IC, it helps a lot.
Please remember - it is your WH's job to fix himself. You can't fix him because you didn't break him. You did nothing wrong.
With time, you can work together to fix your relationship and save your marriage if that is what you decide you want. You don't have to make that decision right now. And just know that any decision you make, you will most likely second guess a hundred times. This will drive you crazy but is completely normal. It is.
I don't want any resentment to linger if I stay with this man
Please note that there is no fast tracking healing. You will resent him and you should. He betrayed you. Don't stuff down your feelings to make things "okay" as they will just erupt further down the road. Be honest with yourself, your feelings and your husband.
Your WH needs to get into IC to do some serious soul searching on why he allowed himself to make a conscious choice to cheat.
Check in with the BF to see if he knows if it was more than once. It's possible but unlikely. Rarely are the WS 100% honest in the beginning. They are still trying to minimize what they have done and protect themselves for further embarrassment. (Although many will say it is to spare the BS of any additional hurt...don't buy it)
You start by taking a deep breath. Collecting your thoughts and defining your boundaries.
This is time for you to define what you will and won't put up with.
Time for husband to buckle up for the rollercoaster ride of emotions he's placed you both on.
Good luck and know we are here for you. You will be okay, I promise.
Good luck and prayers.