Carol,
Please see a neurologist or a rheumy who is experienced with lupus and inflammatory muscles diseases like polymyositis and dermatomyositis. Muscle weakness can be caused by many things and you should not ignore it.
Myositis diseases like polymyositis and dermatomyositis tend to hit the proximal muscles around your hip girdle and shoulders the worst. Symptoms are difficulty in getting up from chairs/toilets, climbing stairs, raising your hands above your head, and swallowing. General weakness often follows and fatigue is always present. Often patients do not realize they are becoming weaker until they go below a level of functionality for a particular action.
There are many other causes of muscle weakness such as ms or md which is why a neuromuscular doctor is probably a good place to start. You should not hesitate. Also keep in mind that you might not have another disease but that your weakness could be simply muscle atrophy and you did not notice it until it got below a level of functionality.
See another doctor.
Bill