You have 153 apprentices right now, it’s quite a lot, so it’s normal to feel overwhelmed. I would stop doing lesson until at least the apprentice number drop under 100 and then start doing lesson again slowly, while monitoring it.
All of them sound extremely difficult with a mid-Genki 1 grammar knowledge. Maybe power through at least Genki 1 before doing anything. But the absolute beginner book club is also a good option.