Without knowing what the cause of this may be, I cannot make a solid recommendation.
If is caused by a hormone imbalance, or even a toxic system, that is a long time for the problem to persist. I am not a doctor, and cannot presume to know what may be causing this.
Having it checked out by a doctor to rule out a more serious problem is definitely in order. I might be able to help you better when I know more about the cause & exactly what it is- so keep me posted!!
