Hi John. Firstly. If you are trying to emulate Griff exactly, then you are in for one long wait!!!
Secondly. I don't know how long you have been playing guitar, but that sounded pretty darn good to me, and you should be more than happy with it. Move on to something else for a day or two then come back to it, and then see what you think of it. You might be pleasantly surprised.
..have a beer or two and beat the tar outta this thing!Perhaps I need to