Sore throat problem??

I recently came down with a sore throat, raspy voice, and terrible cough. I went to my doctor she said it may be allergies because my mom smokes. I say, she needs to recheck. I personally have narrowed my disease possibilities down to:

Croup &

Strep.

I'm leaning towards croup. If it is so, how long until it goes away, and whats the most effective, home cure??