I am so TIRED of SICK!

What is it with kids being constantly sick, so it seems? I kid you not, my girls get sick every 3 weeks. Of course, who else gets sick? Yep, me! I do have to be grateful this time around because I am not as bad as Bryce. He got it worse this time. But seriously, before kids I would get sick 2 times a year...now, that has gone down the drain! What is worse, being in my condition, I am very limited on medicine. Will it ever stop, slow down, or go away? A positive note, at least all this crap is building up Saige and Savannah's immune system....right?