I try to reap until I get 4/5 or 5/5 right to make sure it wasn't the question topic that made me get it right. after 2-3 drills and I see that I'm getting them correct, I move on.

I was doing the same thing and nothing was helping until is started drilling the easier questions first until I got them all right. now am moving on to medium and consequently hard. its always good to start at the easier questions and not to psychoanalyze yourself.