What Causes Loss Of Voice?

About two weeks ago I was having a yawning fit and created a soreness in the back of my throat. The soreness went away after about a week, but now I've lost the tenor range of my voice. Inflection is difficult and I plainly cannot sing without my voice cracking up like I'm a teenager. Should I see a doctor, or will my voice come back on its own (so long as I take it easy).