My voice hasn't fully recovered? waht to do?!?

I lost my voice last Saturday due to a cold...the cold got worse on Sunday and Monday and therefore my voice got worse. I could barely talk on Monday. By this Wednesday, it started getting better( I could articulate better). But that's about it....I can only talk in a single tone....and it's still pretty breathy. If I ven try to sing, nothing comes out- just air. Tomorrow completes a wekek of no voice. I already missed one singing lesson and will now have to miss this Monday's lesson. Will my singing voice come back? Also, my sinus congested hasnt really cleared so I speak nasally an subsequently "sing(or try to)" nasally.