Try contacting "Matthews Friends", a charity for parents of children on the ketogenic diet. I am not sure at what age, children can go on the ketogenic diet, but from what I have heard, it can work for children with Dravet syndrome and some may have a reduction in seizures or achieve seizure freedom? Anyway, it is worth a try, when DC is old enough? (We have tried it on DD, although she has Lennox Gastaut syndrome, not Dravet)
Young Epilepsy runs a helpline for parents, as does Epilepsy Action. The Epilepsy Society has a useful website with research updates on it, etc.
I am not sure what is the lower age limit, but look into applying for Disability Living Allowance. Cerebra has an excellent guide on how to fill in the forms. (You do need help with the forms!)
Has the hospital given you "open access"? Nobody told us about it for years, but it means you can take DC straight to the paediatric assessment unit, if you are worried about seizures, rather than having to go via A & E - so long as they have an empty bed. If paediatrics are full, you may have to wait for upto 4 hours in A and E, but it's worth asking first?