Check out books on dogs at your local library?
This sounds like a problem that isn't completely out of the ordinary.
Also be ready to spend a lot of time and patience now and do not have some sort of expectations that are only resulting in completely ruining your dogs live. You likely might not be able to fix this at all now.
I personally would think about getting a new leash as one way out; it might be easier for him to accept a different one.




