I got sick and I can't sing as well now. How do I get it back?

What should I do to get back my nice voice? I'm 13 and my voice is amazing, or so I've heard. I've heard better than me, but all my friends, family and the people at Hale Center Theater think it is. And if I can't sing, I don't have anything. Singing is my life. Please help me! I don't know how to make it come back. I had Bronchitis, and I forced my self to sing while I was sick. I know I should have taken better care of it. What can I do? It may not sound serious, but I've been miserable with out it. I can't belt out notes like I used to. My voice is soft and I sound like choir girl. lol (I don't hold anything against choir girls, I was one in 5th and 6th grade) Please help me.