Greetings!
Saturn does not give bad influence in higher octave. So problem is in the octave not in Saturn itself. Saturn gives seriousness, ideality, firm principles, loyalty, desire for lasting relationship, preferably eternal one, not just one night crap, because of its long lasting building nature. Low octave is about karmic debts, Apophis (your own evil) and its bad influence. Venus is about relationship karma and how did you treat this world in the past. Saturn is about fixing it. Higher octave occurs when you advanced past your own evil and treat universe better.
Relationship might break for numerous reasons from good energies guarding you from wrong relationship that seemed good only on the surface, to you doing something wrong without noticing it or to another reason. With every relationship wait till the person starts using their real face, because those who wear masks usually wear them for several first months.