i do 5x5 routine this past 6 months,
my trainer tells me that 5x5 routine might fit for newbie and ectomorph like me because the routine itself consist of heavy lifting and more weight on every session.
more to it, it wont make your muscle fatigue so much, and the workout session is enjoyable. you should try if you tired of the routines.
and for the motivation, i did workout for stress release. so more stress, more workout.