Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a history, I can not tell you what your symptoms are from. However, I will try to provide you with some possibilities.
If your symptoms are confined strictly to your left foot and your left hand, this would unlikely to be related to your C5-C6 herniated disc. A herniated disc at that level would possibly explain your left hand symptoms, but would not also cause symptoms just in your left foot.
If your symptoms involve your whole left arm and left leg (or the entire left side of your body) one possibility is that the problem is in the brain rather in the spine or the peripheral nervous system. There could be many possible lesions in the brain that would cause one-sided sensory symptoms, but obviously stroke would be the most pressing and concerning. What in your symptoms is not consistent with stroke is that you mentioned they only occur at rest. However, if you have one-sided sensory loss that was sudden in onset (started suddenly) and has been present for one week constantly, I urge you to seek medical attention immediately to make sure this is not a stroke. Other possible lesions would depend exactly on your symptoms but would theoretically include a tumor, multiple sclerosis, etc. Again please understand I am not implying I think you have one of these diagnoses, these are just potential causes of one-sided sensory symptoms.
If your symptoms are only confined to your left hand and left foot (not other parts of your arm or leg or any other part of your body) then a neuropathy would be another possibility. A neuropathy is basically a problem with the peripheral nerves that supply our extremities with innervation. The causes of neuropathy are multiple but a common cause is diabetes. If your symptoms start to involve other parts of your body subacutely or more gradually, this makes neuropathy a possibility.
I suggest you be evaluated by your primary care physician/family doctor. After he/she examines you and obtains a full history, he/she can determine whether or not your symptoms warrant further evaluation and whether or not an evaluation by a neurologist is necessary.
Thank you for using the forum I hope you find this information useful good luck.
i am not a doc but have you been tested for lyme disease