I know exactly how you feel our courses are only 4 weeks long, it's an accelerated program and it's very challenging. Of course it's going to get more difficult the further you go up. But if you really want this, you can do it. Try and figure out what you did wrong and change that to help you do better and to pass. When I study I have to have NO distractions and it has to be quiet. I do highlight important things then I go write them down and say them out loud to myself. I always ask my instructor for help or I go straight to tutoring. You're not going to learn everything, some of it will come from experience.
If it's been done before, it can be done again. Do not give up!
Good luck :)