Do not beat yourself up because you are not learning as rapidly as you had hoped. Everyone's rate of learning varies according to the topic, to how well they are feeling and to circumstances. In a technical sense, two of the parameters of learning are how much you know (prior knowledge) and how long you can spend learning (time on task). I am not giving you two excuses, but one does have to learn according to one's situation. Accept that we all study from where we are at to where we want to go. Teachers can make it harder or easier for you up to a point; but never impossible. Your teachers do not make you - you, the learner, makes you into the person you want to be