Hello, thanks for using HCM.
From what you are saying, it seems you are having a chronic and progressing arterial problem. Blood supplies heat to body parts and when blood supply is limited, the underlying body part becomes colder than the other parts. A common arterial condition that could be responsible for what you feel is artherosclerosis which is common in hypertensive, obese
and diabetic patients.
On the other hand, other possible causes could be of nervous origin probable from a nervous compression from trauma or irritation from metabolic diseases like diabetes
or from viral infections.
A detailed examination is however needed and possible tests done in order to have an apropriate diagnosis and so, i will advice you see a neurologist