Oh, man! :(

I am sorry that some of the health professionals you are dealing with are being so unhelpful

I completely agree re wanting to avoid risk of further head injury, and can see a strong argument that if you do switch to Keppra, it should be after your existing brain injury has healed up more

(and also other safety precautions, which might include

a) being in hospital

b) having a friend come and stay with you for a few nights

c) wearing one of those padded helmets disguised as hats/beanies designed for people who have seizures to prevent head injury like https://dejay.com.au/ribcap