But is clearly not himself please help

You gave us very little to go on, but I would be inclined to say that if your dog is not himself, and not eating or drinking that you need to get him in to a vet sooner rather than later.

I agree with lady Sam, there is not enough info jere for us to go on, you better take him in to see te vet. Could be a number of things and we'd really only be guessing.