Maxidex and struggle

I have been taking Maxide for over 8 years, and now I have severe weakness in my legs, and have to struggle to keep my balance. When I go to bed at night, my legs feel as though they have littlle people running continuosly in inside. I mentioned this to my Doctor, and he suggested that I take half a tablet each day. I also had a serious problem with my potassium level being at a dangerous point at one time, and not I am taking prescription potassiun every day. Please give me some information on these problems.

Thanks