For me, everyone is different.... 90 credits at level 1 is very manageable and 120 is doable. I studied 120 credits per year for the first two years, thus getting the first two years of my degree out of the way rather quickly. It worked out about approx an assignment every 2 weeks. You just have to stay really strict and committed to reading every day, for me it was an hour -2hours after work while in bed.