Sounds like its dying back for some reason - check for infestation or disease, otherwise, if my memory serves me right, I believe Alabama had some snow a while back, unusually for you guys? In which case, it might be the cold that's affected it. If you can't find any bacterial or fungal infection, nor infestation by any insects, then wait till the weather's warm in early summer and cut back to healthy wood and remove all dead stems.