I have had a sore throat since Nov. and it gets worse at night?

I had bronchitis in Nov. and was able to get rid of it with antibiotics. Ever since then I have had the worst sore throat that only seems to show up at night. It hurts so bad that it even hurts to breath. Lately I have been losing my voice in the mornings and it comes in and out all day. Any idea what the problem may be?