Please help....dog behaviour issues :S

hiya, im relatively new here but i have had dogs all my life, i grew up with isaac from when i was four
i sadly lost him when i was 17, and now im nearly 21 i missed the company, so bought myself two jack russells in january. we have a labrador at home already, she is four in august, and mine are 1 in the october, all three are bitches.
however, last sunday, for some reason, their hackles were up and they started to growl and then to fight. its been over a week now, and they still dont get on. we have to keep them in separate rooms, we have a room built specially for them and they have their own outdoor paddock, with good bedding out there, so they arent just 'shut out'. we just cant get them into the same room, or within distance of each other! they fight through the fence between paddock and back garden and through the glass window by the door to their own room. we phoned a behaviour specialist and vets and we have done everything they advised and still no difference, if anything got worse! we have tried: confirming the alpha status of the labrador, treating them all the same, treat based methods, walking in a field on lead getting closer, making a fuss of them in front of each other, words of encouragement, we have tried everything suggested!
any other ideas...???
i have asked friends of mine who breed and are vet nurses, and they said that if it continues, consider rehoming my jack russells
so any help would be appreciated!
thankyoooooooooooooou!
nickieloux