Discouraged

I'm sick again. I just got over my cold/pink eye/ear infection a week ago and I've already come down with a new set of ailments. This time I've got the flu and strep throat. My patience is wearing thin and I feel like I can't take this much longer. It seems like every time I get well, within a week I'm sick again. I take my vitamins, eat a balance diet and get plenty of sleep. I wash my hands obsessively at work and try to have the kids do similarly. I try to take care of myself, but it seems that no matter what I do I get sick. I've been sick more in the last month that I was the entirety of last year. I'm just worn out. I can't keep up with these 50+ hour work weeks when I'm sick. I just can't. Anyone have a miracle cure all for me and my no good immune system?