Find a GOOD singing teacher. Get a teacher who understands the mechanics of the voice, not someone who is just an accompanist teaching songs. A good teacher will treat each student according to the student's unique strengths and weaknesses. Reading generalities about breathing can only go so far... you need a teacher who can watch what you are doing when you sing and guide you with the correct exercises to build up your breath control and use your breathing correctly. Contact your local musician's union or university to find a teacher.

Alice