muscle cramps/weakness/fatigue

[cathorne]

For quite some time I have endured a cycle of fatigue. About every three weeks, I tank and need almost a whole day or two in bed to recover.  I spend about 7 to 10 days a month like the walking dead.

In addition, for several years I have night time leg cramps.  To be clear, it began as inside thigh muscle cramps and escalated to the point where several nights I would have inside thighs, calves, shins and feet cramp all at the same time.  Taking mega doses of magnesium (about 800 mg a day) keeps this his to a minimum.  I have been tested for potassium etc, all normal.  At one point my doctor considered quinine pills, but my insurance company declined it.  
With the magnesium, I now treat it with scalding hot baths and/or biofreeze which I apply liberally to my legs.
Occasionally I get cramps in my biceps and hands during the day.  More recently, I find that there are certain positions, that often produce immediate cramping, such as washing the floor and my hands and knees.  It does not happen all the time, but it does happen often now.  
I recently saw a cardiologist and passed the stress test.  I saw him because I started having this cold burn sensation in my back and chest and arms. It is intermittent and I have no idea what causes it.  
I am increasingly more fatigued with exertion but it is not consistent.  Some days I have energy and mobility and other days I do not.  I have tracked sleep and diet.  I can't find any common issues that help.
I did get a shot of prednisone a couple of months ago and I felt WONDERFUL for about a week and half.  
I am 58, 8 years post hysterectomy. I have arthritis and take fish oil, glucosmine and condroitin, as well as bio curcumin which seems to manage the arthritis discomfort pretty well.  
I try to stretch every morning and often ride my exercise bike for 30 minutes.  I do have bad knees and there are some days they are just to cranky to ride and others where I am fine for 5 miles.  I find that some days, such as this morning, the stretching and leg lifts without weights produce cramping within the first few reps that require that I stop.  This morning, both biceps, a stomach muscle and the back of my thighs cramped within the first ten minutes.
I have spoken to my dr.  Was sent to cardiologist who said it's not heart related, was sent to rheumatolgist, and while I thought he was dismissive, he said it wasn't inflammatory.  SO.....
Does anyone have a suggestion to get this under control.  The fatigue has been persistent for several years and the muscle cramps are increasing.
Recently I also feel like I drop things more than I ever did. Small motor stuff.  
I should also mention that I have ARC, and have severely torn both rotator cuffs and had them repaired. I wondered if there neurological problem associated with this, but the leg crarmping and fatigue pre dated those injuries. The arm and hand cramping may have begun after the first rotator cuff surgery ,but I am not sure of that.  
Any suggestions are appreciated.