<human>: Can you give me the gist of the text in a nutshell?

I am the worst person in the world. I don't know how it happened or why it happened. I cheated on my fiance. Not only that, he walked in on it.

I was the one person he could trust and I fucked it up. He's been through similar situations with past girls. His trust was broken so many times by so many people. Now I'm just a name on that list.

I can't even conceive why I did it. It was with my best friend. I'm assuming there was some under lying subconscious stuff going on that I don't know about. I never thought about doing anything like this. He made a move, I didn't stop it. I should've stopped it. I should've ran. I never wanted to do this, never thought I could do this.

All I want is the love of my life back. He's so angry, understandably. It hurts so much. I can't eat. I can barely sleep. I need him. He won't talk to me. I'm living five hours away for school right now and I'm all alone. I just want him back. What do I do?

I know this whole post may seem dumb when I put the ages. He's 22, I'm turning 21 in August. We've been together for a little under two years. We were engaged at six months. I've had enough previous relationships to know he is the one I want for the rest of my life. I just screwed up my chances royally.
<bot>: I cheated on my fiance with my best friend, he walked in on us. I just want him back and advice on how to get him back.