How can I be sick AGAIN?

I am sick. AGAIN. How is that possible? I was just super sick in January. Maybe I'm just doomed to be perpetually sick. At times, it feels like it. One of my law school classmates once asked me if I drank the cold virus for breakfast...perhaps I do somehow and don't even know it. It's not like I'm teaching kids, which explained the strep throat twice in two months my 2nd year of law school. And I don't see Charlie and Matt enough to blame it on them. All I can think of is stress and lack of sleep. Maybe that's it. Who knows? Regardless of cause, I just want to feel better ASAP. Though, figuring out the cause is probably important too, as I don't want to be sick every month. Anyone have any thoughts/advice?