Hi Esme , poor baby he is all out of sorts , dont think there is going to be a quick fix to the situation other than maybe start from scratch again, wipe the slate clean and try small things to get his confidence up .does he get excited at the prospect of going for a walk or does he go reluctantly , maybe put on his lead and go out but just walk 50 yards, stop him make him sit reward him then head back home , he could be expecting something bad to happen so if he can learn going out doesnt have to be bad , he wont expect to just go back so you,ve broken the expectation and the stress and it should lessen the anxiety, You could try this as often as you feel compfortable doing it or untill the neighbours think your mad lol . but each time go a little farther and alternate the direction you go out but each time make sure he sees you as the leader be strong dont wait for him to respond to something negatively keep a pocket of something tasty to hand and praise him all the time if something startles him keep it in your head that the best things come to those who wait . keep us up to date
Andrea