I feel your pain!
Last January (2006), upon returning from our WDW vacation, I found out that I had it. That was the beginning of a very sick year for me. I had 8 cases of Strep that year!! It seemed that every month, I was getting sick.
My husband only had it twice that year, my sons had it twice also.
My Dr. did a lot of tests on me for immune system problems and all. Everything was fine. She asked at one of those many Dr visits had I been getting sleep at night and I hadn't. She said this could affect the immune system. She also told me something I didn't know with Strep.
I had been throwing away my tooth brush when the symptoms of Strep were gone. She told me to purchase 2 new toothbrushes. I needed to begin using one new toothbrush on my 1st day of beginning the antibiotic...when the antibiotic is done and the symptoms are gone (5 days to a week later), throw that toothbrush away and use the other one.
Apparently, this is the trick that worked. I started getting 7/8 hours of sleep and tried the toothbrush trick. Knock on wood, I have been Strep free for about 4 months now!
It's so funny, after being that sick for so long. When I feel that little tingle in my throat now from a cold or allergies, my first thought is

!
I never want to have Strep again!
Good Luck!!