You may be having pain from more than one source- PAD may be one (which I talked about above). Diabetic neuropathy, one website says can cause jabbing pain that's sharp, which may be worse at night and you can have pain when you walk. Also, it mentions how you can be extremely sensitive to touch, even with a sheet, it can be agony.
Restless leg syndrome, another web page lists can be felt in calves and thighs and some of the descriptions patients give of their symptoms include: cramping, painful, aching and more. See private message for more details.
It sounds like you have diabetic neuropathy. Damage to peripheral nerves will frequently present itself initially in the feel and legs. Nerve damage results in muscle shrinkage and pain. See:
http://diabetes.webmd.com/diabetes-neuropathy
Peripheral artery disease or any form of peripheral vascular disease can cause pain in your extremities. The pain is caused by ischemia, lack of oxygen to tissues. It happens when plaque in your arteries (in the case PAD) builds up so much that it winds up totally blocking them, causing whatever is below it to be oxygen starved. It can kill the part of the blood vessel (including the little capillaries below the blocked spot. The lack of a proper oxygenated blood supply can potentially cause gangrene, like it did with my grandma. A doctor told my grandma she had a lot of grit, because ischemic pain like she was having was equal to the pain of a heart attack, only worse, because it is prolonged pain.
It is very important that you be sure your cholesterol- particularly your triglycerides, which are involved in plaque formation get into/are in normal range. You need to be careful about medicine, though if you are taking it, because muscle cramps in your legs can be a side effect of the statin drugs. See private message for more info on triglycerides. There is a treatment a sibling recently heard about for peripheral vascular disease- where they put stents in blood vessels in your legs to keep them open. It would have been nice if my grandma had been able to try this.
Another thing that can cause muscle cramps in your legs is low potassium- did your doctor check this level in your blood?