Keep encouraging soft food every chance you get, as well as, syringing water, then make it your first priority to get your kitten to the vet when they open first thing.
Sounds like a possible head injury, poisoning or a virus your kitten hasn't had shots for yet. We can only guess; your vet will know.
Please let us know how he/she is after.
I think you need to get the kitten to the vet. It sounds very serious.
I have given it milk and water with a syringe.