Depending on where you live, I know of a wonderful coach who specializes in repairing voices, whether they have been damaged through poor technique and teaching, or physically such as ruptured folds. People go to him from all over the world. He is a speech pathologist. His name is Dr. Thomas Houser. He practices in New Holland, PA. He also does workshops in the summer at Marywood College in Scranton, PA. The Houser school of singing is very gentle and emphasizes awareness of your own voice box and body. So it will not be an overnight thing, but it is designed to make your voice last and be vibrant for the rest of your life. Regarding books and tapes for singing and vocal technique I can highly recommend Paul Newham's Voice Movement Therapy. He has a six tape set called 'The Singing Cure' and several good books. There may be a practitioner in your area. I know someone in upstate New York. I do recommend one on one teaching to get feedback.