I commend you on your commitment to a Sexless Serena start! I just posted a save about 90 minutes in for another person, maybe that would be a good jumping in point?
I'm not sure which version you played, but I remember it becoming quite difficult to maintain a Sexless playstyle even when I first started. Constantly turning over every used rubber out there for scraps of sanity...
It's now much easier to get sexed (and wildly easier to manage Lust and Sanity), as Eve pretty much railroads you into it, even if you don't hook up at the bar or follow school questlines (and events) up to their sexy content.