I guess this is a sort of oneitis, except I cant really apply many TRP values here.

Background

I'm 16, graduating high schoolthis year. Last summer a girl invited me to her place and initiated sex, culminated with her naked, me (doing my best at) fingering her & everything but didn't go any further because I couldn't get a boner. We spoke after, she seemed very uninterested (as opposed to really digging me before) and didn't answer my next messages, so I stopped talking to her and haven't seen her (different schools) since. I was (and possibly her) a virgin before this, and still am.

The issue

What's annoying me is I can't stop thinking about her, whenever I think about sex she appears and I can't stop replaying/seeing the scenes where I fucked up.

I'd really like a way to stop thinking about her whenever there's sex on my mind.