Sprache lernen im Vorübergehen!
Good preparation also includes a structured approach. This means that you pack the topics into individual blocks and work through them instead of just learning at random. You should also keep an eye on the time. Depending on your learning speed and the scope of the topic, you should calculate how much time you need to study and repeat. Bulimi-learning the night before the exam makes no sense and only leads to stress.
A coherent learning structure also requires a certain amount of variety. Your German vocabulary training should not be directly followed by French vocabulary. This makes it unnecessarily difficult for your brain.