Me and my girlfriend have been together for a little over a year now. Near the beginning of our relationship I made a stupid decision and made plans to hook up with another girl. After we had parked the car and started kissing I stopped her because I couldn’t get the thought of how much this would hurt my girlfriend out of my head, so I drove her home. The next day in class she told basically everybody she knew that we had slept together, and it crushed my girlfriend. I hated seeing her this way because of how much I truly did care about her, and so I lied to her and told her that the other girl had made it all up and I had just given her a ride home. Fast forward a year and some change, throughout which she had never truly believed that we didn’t sleep together, and were having a big fight about something, I can’t even remember, and I couldn’t hold it in any longer so I told her about it. She was so crushed about it, and hence rained down the full emotions of every time I’d tried putting off telling her because I was scared I would lose the really only thing good in my life. We’ve talked a lot and I think she’s a little settled about me not telling her, but she doesn’t understand why I would have done it. Me and my girlfriend had already been having sex at the time, and she’s much prettier than the other girl, and she just wants an answer, but the problem is, I truly don’t know what the reason was. Having a reason would start me on track to fixing my mistakes, but I don’t know why, and it’s eating me alive. I don’t know what to do. All I know is that I can’t lose her because she’s the only thing holding me together. The worst part about this all is that I’ve moved away from my hometown for college, about a 3 hour drive, and she’s still in high school, and I only get to see her every other weekend, except the rare occasion that she comes to stay at her dad’s house, which is  a little near me, for the weekend. Please help me