IVAN JANEA

My 4 month old pitbull is extremely afraid of walking, at first when we adopted him he was fine aside from him not being leash trained, he was not afraid to go for a walk. Now he won't go for walks out of fear. He either sits down with his tail tucked between his legs, or lies down or pulls on the leash, even going as far as to jumping to not go for a walk. I'm not sure what's the main cause of this, but I've tried taking different paths, and treats. He is also teething right now if that might correlate, it is also not too hot or cold when I take him for walks, about 17-20 degrees celsius with a cool breeze