About rabbit. Kind of unknown disease!

Hello sir I had a female rabbit she wasn't eating, pooping and urinating for the past 2 days Also she had a clotted yellow mucus with pallets of poop over her anus we removed it today with soap water very gentlely We don't have any vet near us so we use the online platform to see for a doctor He recommended liv52, montac and rumen fs powder Also we used to feed her paste of coriander leaves through syringe. But it felt like she had no energy left in her body Today at 3 pm her heartbeat gets very slow and then she was unable to even stand or lift his limbs In next 30 min she started very abnormal behaviour and she was getting sessors Her mouth gets wide open, her neck gets completely erected and she was moving her forelimbs. Watching her dying with such pain and action was very difficult for me So I wanted to ask sir is this happens to all the animals when they die or its reaction of some medicine Or she had some kind of unknown disease