I don't know how much time you have left until step 1 but I would really suggest that you focus on your weakest areas. If you're not sure where to start, first aid is probably the best place. Seriously sit down and memorize the sections you're weakest at. You'll feel like you're actually learning and when you see questions in your weak areas, you'll be more confident since you'll have an "arsenal" of knowledge. Another way to improve in qbank is to carefully go over all the questions and make notes of important questions you missed or important concepts in questions you got right but aren't too strong in. I too was feeling like you because my scores were pretty much the same for a long period (~70%) but after I tried the suggestions I just made, my averages are around 77-78% now for 50 question random blocks. Good luck, it's doable, but don't be afraid to just start memorizing! I truly believe the only way to feel like you can "conquer" the test is just to memorize as much detail about everything as possible... Of course this depends on where you're at in your studies and how much time you have left.
Oh, and another point... qbank (as I"m sure you noticed) has quite a few random off the wall questions and plenty that aren't written well... If you feel like you know you're stuff but you're missing the random questions, don't worry! You're probably right on track!