What could I be sick with?

It started out 7 days ago with a severe sore throat, and that's all I had for three days. Then on the fourth day I started getting congested and I figured it was just a cold because I also have severe ear pain in my left ear. But today I've developed diarrhea and my ear pain has worsened. None of my other symptoms have gone away (still have a sore throat) and now it seems to be moving into my chest (getting croup is not uncommon for me). I've just never been sick this long and my mother's pushing me to go to the Dr. and I just can't afford it. What can this be?