I have tried Essex Rider, Boards at Ingatestone, Upsons Stabletalk, Equine Adds, Driven all over the place looking I dont want much stables and menage that I can work them in not even worried about the hacking, just anything
Theres a couple of yards around Braintree and I know of one at Coggeshall, it might be worth popping in to see if they have vacancies?
Also try asking Jacqui at Braintree Riding Club, she has a yard at Bocking but also knows most people in the local area.