A cheaters heart

Well, I never thought it would happen. I mean, of all things, I really never thought it would happen. Sean has cheated on my twice, and each time hurt more then you can imagine. The first time was back in September, when I was at home and he went out with a few of our friends. Then, When I was a little concerned, I decided to catch him, and I did. And while I have forgiven him for it both times, I was still really hurt by the whole thing. And then this happens. I cheated on Sean. I cant say why exactly. Part of me was angry at Sean, Part of me wanted to show him what it felt like. Part of me was jealous that he was able to explore this venue and I wasn't. Part of me was just horny. Of course I told him. How could I not. I betrayed not only him, but us, and me as well. I betrayed everything I stood for in this relationship. I've cried about it for a while. When I told him, he threatened to go out and hook up with someone to get back at me, which would have ended us for sure. Things are so fucked up, I don't know what to think. I don't even know if we are going to last anymore, when just last week I heard wedding bells (Maybe?) in a few years. What does one do when faced with such heart wrenching pain? IN the end, he forgave me, as I forgave him. Did I deserve to be forgiven? No. Did he? No. So what do we do? I love Sean with all my heart and Soul. I want to give him everything of me, and now I have given someone else my body. Will Sean ever trust again? Will I ever trust him?