violet09
Seems as if you've been together for a while, but you weren't married very long before the affair began. If you look back, why do you think it not only happened, but happened so fast? What were you feeling at the time? What do you think you were looking for from this affair? Do you think that something about being married triggered some kind of memory or response in you? Were you ever molested or neglected as a child, or did your parent's fight or divorce maybe? Are there reasons you might have unconsciously tried to self-sabotage this relationship?
I would recommend therapy, if you can. My advice is to start with a personal therapist. I think understanding your reasons, your needs, and your boundaries, would be helpful before trying to understand how and why those things failed both of you in the relationship.
If I may offer some advice... I know right now, things are incredibly painful for you, and you are probably feeling scared and out of control. I get that. You miss him. You fucked up and you know it, and you want him back. All good, understandable things.
To him however, all of the things, those feelings... well, it's a matter of what you say vs. what you do. You say you love and miss him, but to him, you chose someone else over him, lied to him, betrayed him, broke trust... and it's impossible to reconcile "I love you" with "but I was sleeping with someone else". One negates the other. Understand? To him, you needed something more, more than him, and you just went and got it, to his detriment. Now, you are saying that you miss him and love him... but to him, those again are just things YOU need, and are trying to get. He doesn't see himself, his needs, his pain, in that. He just sees you getting what you need.
He understands what you did. He knows you are sorry. He just isn't sure if you're sorry that you did it, or that you're sorry you got caught. Since you lied so much to him (to be clear, I'm not picking on you, we ALL did the same thing) he HAS to assume it is the latter. Which again, in his heart, may feel like being cheated on all over again. It can feel as if you are still putting what you need, over what he needs, and he keeps paying the price for it.
So think about that a bit. Since words don't matter right now, actions are the only thing he has to go on. And to that end, if he is even to consider staying, he needs a reason to. "Ooops, I fucked up" isn't a good one. Instead, he needs to see change. He needs to see you going to IC, support groups, here. He needs to see you sacrifice for him. He needs to see you put him first. Most of all, he needs to know that you see and feel the pain he is going through, and I mean really understand it. And that will take time.
Take some time to reflect and figure out what the hell happened and why. And keep coming back and reading, and asking questions, there is a lot of wisdom here to be had.