I was wondering if you ever found out what was going on with your symptoms?
Thanks
I presume this is a new condition? If it was one leg I would be concerned about a DVT or cellulitis; One leg would also be the normal presentation of sciatica. But both legs, acute onset... I would lean toward a spinal condition such as spinal stenosis from a broad-based, central disc herniation that is affecting both sides of the spinal column. Otherwise I would think of things that would cause aching in the muscles, as the legs have the largest mass of muscles in the body. Some people get severe aching in the legs during viral or febrile illness...
As I re-read your question you mention 'always worse when sedentary'. The obvious treatment is to keep moving... the weight loss would likely add some years to your life as well as reduce the leg pain. I don't have a great answer, though, except for the general statement that your muscles seem to be tightening up at rest; it might just be a consequence of the long hours you put in along with the aging process. Some general conditioning, and stretching exercises before work, might be helpful.