I hope this helps. A long one for me!
I'm 4 years out of this situation and I was going to ask how old you are? Reason being my hormones went totally crazy and I fell for a complete tool of a guy, I was so so in love, obsessed, happy, excited and just loved the secret and the special messages and attention.
I had what I now know is called "in plain sight" affair, he was a family friend came to our home, was part of a friendship group and we thought we were so clever.
Hindsight is great and I can now see him for the twat that he was and I can see myself behaving like an idiot as well. In the moment it felt real, it felt amazing and I got totally swept away.
My marriage has never really recovered if I'm honest I've lost my DH emotionally, he knew deep down what I was doing and he distanced, I've distanced through guilt and it's never felt the same. It's ok, just about.
The sooner you can get away from this the better and the less damage it will cause.
Mine was a perfect storm of hormones, right place, being taken for granted by DH, low self esteem, being selfish and stupid.
He was also the polar opposite of my DH, My DH is passive and laid back, this guy was 100 miles and hour crazy, funny, silly and ambitious.
All combined to me falling for the nonsense of him leaving his wife.
All I can say is thank god I didn't carry on, it was hard to finish, he was like a drug but we gradually slowed and then stopped contact, he drifted out of my life and now I have the odd glance on LinkedIn at his photo and I have nothing, no feelings at all just grateful that I was strong enough to walk away, I do still miss the buzz of having that secret but I've filled my life up to the brim with good friends.
During lockdown I reflected in what a nightmare (high energy) he would of been.
I hope that helps you see a future without him, if someone had told me this 4 years ago when I was in the thick of it.. I think I would of struggled to end it as well.