How do you next a oneitis that you feel guilty about doing so to?

I had about three genuine female friends lasts semester (girls I enjoyed being around without the possibility of banging). This girl was one of them and she helped me out when I really needed her.

I have no problem getting pussy from other plates because I have a high SMV in my environment. When it comes to forgetting about this girl, how should I go about it?

EDIT: Just wanted to make it clear that after already becoming good friends we were FWBs for a while. Then she ended it before the summer, but I could see it coming before that.