I'm so sorry to hear all this that's been going on . I live 4 doors up from you and you know me , please call round or I'll call round to see you ,you must feel quite shaken . My dog suffers the same anxieties but as you know mine is rescue and older , I think you have every chance to nip it in the bud . I myself have only heard them occasionally and there are other neighbours to you with dogs that bark too at cars outside . I personally think it's totally out of order somebody threatening you like this , don't forget I'm here if you need help x