It will take some time, and patience but he should come around. What he needs right now, is lots of love and attention. He needs to feel safe. You need to get down on his level when you want to give him attention, dogs feel more comfortable that way. As far as getting him used to the leash, have you tried encouraging him with treats?? that always seems to work! I am sure there are more people on here that could give you much more advise. Good luck!!