This will sound stupid but it was just a thought. Can't oneitis be a good thing. Let's say your attracted to this one girl and you really care about what the outcome with her but you only have that mentality with that one girl. You put her on a pedestal and look down on all the other girls in your life. You begin to not care about any other interactions other than the ones with her.
Doesn't that give you some kind of outcome independence with all the other girl. Becuase you just don't give a fuck what happens with them.