I'm not a doctor of course, but after a very stressful year (let alone 13 years), my feet are almost always cold, until mid to late evening, or if I'm distracted by something pleasing or funny. Had a 24 hour salivary cortisol test done a few months ago -- came back very low in the am (the opposite of normal), then it shoots up high at noon, then comes down a bit to a more almost normal levels later in the afternoon and at midnight. Another test more recently suggested I'm in adrenal burnout, which is no surprise.
STRESS (especially prolonged, intense stress)...excess (and then eventually low) CORTISOL...might be causing your cold hands, cold feet...not to mention poor immune function, poor digestion, poor fill in the blank___________.