reaccuring throat infection

I have had a reaccuring throat infection now for the past three months, that will go away with antibiotics only to return a few weeks later. the infection consisits of swollen tonsils and glands in the neck, and some ear pain. No fever or coungh. I have been tested for strep throat and mono, both were negative. And i dont believe it is contagious as none of my faimy of friends have has this problem. the throat infection as accured five times now. . other than the antibiotics, i take advil for the pain (which helps somewhat) gargle with salt water, and sometimes use oil of oregeno. Any opinions or suggestions would be very much appriciated