After 3 years of healing, scar maturation, and nerve regeneration, you are unfortunately in a minority of patients who have not accomodated to their "new normal" after surgical recovery, which in fact IS as complete as it will ever be. There are still things that may be of value here, and this will require a return visit to your surgeon, or consultation with another who is willing to address your concerns. For your part, you must realize that scar tissue and sensory nerve injury associated with surgery is permanent and cannot be "taken back," just as many if not most mothers who have had C-sections note some degree of numbness around their incisions permanently. This goes with any surgery in any location, but you do have several components that may have some addressible value.
One of these is the tight band-like sensation that runs from under your jaw to the top of your head. If your surgeon used a permanent suture to act as a neck-tightening and jawline-defining part of your procedure, this could be cut, released, and the band-like tightness improved. But this will work only if your surgeon used that very specific technique and permanent suture that obviously is still too tight, and will remain so until released. The loss of appearance improvement may actually be worth the improvement in reducing the tightness and aching pain, if that is indeed the cause.
The altered and numb sensations you describe are likely permanent, and passage of more time will not make any additional improvements other than what your mind and awareness can adjust and accomodate to. Desensitizing massage, biofeedback, acupuncture, TENS units, or other options may exist as possibly-helpful options for you to consider. These would be discussed by a pain specialist, neurologist, or physical therapist, in addition to non-traditional medical providers.
You should also read Dr. Steinsapir's thoughtful reply as well. Yours may be a complex situation that would benefit from consultations as he suggests. This does NOT mean you are "crazy" or that your symptoms do not merit serious consideration, but that you may benefit from psychologic techniques or neuropsychiatric medications to help you overcome awareness of these sensations.
If they are "not that bad" and you were just curious, these symptoms don't mean that you have a problem with your healing or any sort of concern to be worried about; it's just that you are in an extremely small subset of patients who remain aware of the normal effects of surgery when most of us get used to them and forget that they are still there. Everything is in different degrees for each patient. Best wishes!