Sick of being sick!

I'm sick of being sick! Yes, my ear infection that I had a couple of weeks ago went away but last week, something else sprung up--or I just never got over what I had before and it's back! I have a sore, scratchy throat and a cough, all of which I had right before the ear infection. I also just found out that mono is going around the school where I work--could that be it? There are also bad allergens in the air and we are in the process of building a new school behind the old one so, the construction dust is bad. So, am I really sick or is it just a mixture of allergies and dust? If anyone out there has any ideas, please share! I'm sick if being sick!!!!!!!!