Well maybe your 2nd time will be easier?
Remember, it's just a job. Being cabin crew isn't rocket science. Yes, we are responsible for safety etc etc but compared to doing a PhD...
As long as you study and revise I don't see why you wouldn't pass. Seek support from your trainers too.
You sound like you are a very good flight attendant, just think of the end goal and keep that in your mind. THINK POSITIVE.
Good luck!