Struggling with Russian at university

Hi all,
I am currently studying Russian (beginner) and German (advanced) at university and I am really struggling. I am on my 6th week of learning, and we cover exactly 1 unit per week, with one bi-weekly test on the previous 2 topics. Units we have covered in order of weeks have been; the russian alphabet, plural nouns and adjectives, the prepositional case, the accusative case, the genitive case, and this week we are covering nouns and adjectives in the accusative and genitive case. We get 6 teaching hours a week (excluding study hours and homework), including one oral session, and I am in a very small class (12 people), but I feel like I am the one furthest behind. My friends in my class also say it is really hard, but they did much better than me on tests, and I struggle to grasp the concepts of when to use the genitive and accusative so I often use the wrong case.
I feel like as soon as we have finished a unit, I am expected to know everything and move onto the next, when in reality it only took me this week to fully get to grasps with the accusative - I am still shaky on genitive. There is also an extreme amount of vocabulary we are expected to memorise, and my teachers aren't very forgiving, and out of everyone in the class, they rarely ask me to answer any questions.
I think I could manage the workload if I only took Russian and German language, but I take 3 other culture modules which also have an immense amount of work to do, so I am starting to feel really disappointed in myself and I fear I simply am too stupid for Russian. I knew it was hard, but I am at a B2 level in German, so I figured I could manage but I am becoming increasingly demoralised by the day, especially as I am basically doing schoolwork from 9am to 9pm. Any advice would be appreciated as I really love Russian, but it is causing me many breakdowns.