Thank you for your question. It sounds like you've been around the block with this issue. I have to say that the brief history you provide is not really enough for me to offer an informed opinion. There are several conditions that could cause the symptoms you present with, from a simple mineral deficiency to a more complex nerve or rheumatological disorder. Without a proper history, examination and some testing I cannot answer any of the questions you have asked.
I would recommend making an appointment by calling 076-229-4662 if you would like to pursue this concern with me.
Many thanks and warm regards