Why am I sick all the time?

it seems like every time i turn around, i’m sick. Like five months ago i had bad tonsilitis and then just shortly after i got so sick they thought i had the flu and i was on quarters (in the military, it means i have to stay in my house for however long the quarters say in order to get over being sick or to recover from something), well about two months later i had a pain so bad in my side that i couldnt breathe right and i was in tears and naseated(sp?) that i had to go to the hospital and the doctors argued about ovarian cysts and appendisitis(sp?) so they did nothing but dope me up and keep me over night. well like two weeks ago i was on quarters again because i woke up at like 3 in the morning and couldnt stop throwing up, i was in crap shape all that day. well today i wake up and i feel like i’m going to throw up and my head is throbbing. I hate this more than anything, i’m tired of being sick all the time, and i’m tired of my doctor not caring (military healthcare, YEAH!!!! insert sarcasm). It just seems like nothing i do works either, like herbal teas or prescribed meds. i’m sick and tired of being sick and tired, i’m also tired of having no clue whats wrong with me, anyone out there in flutherland have any idea what might be wrong with me or what i might be able to do to strengthen my immunity???