Dating advice from pre frontal cortex ?

Hi, I need some help with my dating life (again…). I notice that whenever I meet someone, I will project my relationship manual on to them, even when we’ve been casually dating for only a few weeks (or even days). I am super casual in the flirting phase, not really attached to the outcome, but as soon as we start having sex, an emotional switch goes on (or off), I get super attached, I start thinking of him as my boyfriend and expect him to behave like my boyfriend. Which leaves me feeling disappointed and rejected as soon as he doesn’t. Looks like my limbic brain is running the show… How can I overcome my biological impulses (which, by the way, create lots of unnecessary drama for me) and start dating with my prefrontal cortex instead ? What would it even look like ?