How can I move on and forgive myself?

If it has been so long since it happened and no police have been involved then you should stop worrying. It is likely that you may have played the incident up in your mind to be worse than it actually was. We all try things on when we are young and having a good time and sometimes the feelings aren't reciprocated. You obviously still feel bad about this so I don't think you fit the profile of a sexual deviant. Relax and lighten up on yourself. You know that isn't the way to behave and you have punished yourself long enough.