Really feel for you. Your cat is very like ours - and I'd be devastated if I lost Sprocket.
Like others, I've had various cats go missing over the years and all have turned up or been found. Keep looking, keep calling him. And I know it sounds daft but look everywhere in your own garden and next door's - I once found one of my cats hidden in some bushes in my neighbour's garden with her paw stuck through her collar (the cat, not my neighbour). Oh, and another of my cats fell down the back of a book-case - she was completely stuck & couldn't get out.
Might also be worth letting your local vet know plus anywhere someone might take a cat they've found - Cat's Protection League, RSPCA, PDSA, Blue Cross and any local catteries.
I hope he turns up soon.
1993 Cannondale Killer V - ancient & battered like its rider.
A newish Dawes road bike called Jim and a 2004 Claud Butler Cape Wrath.