Should Jaw & Lower Mouth Pull So Much That Talking and Eating is Difficult After SMAS Face? (Photos)

SMAS fixation near the temporalis fascia causes discomfort when eating or moving your lower jaw for up to a few weeks. This is normal and expected.

Here are some general comments that would include the rest of your concerns:

Everyone wants an immediate result - including surgeons! Unfortunately this just isn't how we heal.three weeks  is just too early to tell. There are many predictable portions of the healing process that ALL PATIENTS EXPERIENCE. Although both doctor and patients would like to not have this happen, it is part of the healing process.  Massage can some times be of benefit during this time period These Side effects refer to what you will be experiencing from the facelift healing process: Here are some of the common things you will experience. The common side effects include: swelling which is maximum 2-3 days later, bruising (highly variable), numbness which takes several months to resolve,  tightness takes several days to months to resolve, discomfort chewing (technique dependent), discomfort (generally mild with this surgery, nausea (variable) and in some patients emotional lability in some. Although most of the visible edema resolves in 2-3 weeks in mini-lifts and 3-4 weeks in traditional facelift approaches, residual firmness (edema you feel but don’t see) can linger for several months. Skin suppleness also takes a while to return as does scar maturation. I tell my patients it takes up to a year for final resolution of the healing process. In my experience, the above rough time table is usually delayed in smokers, when multiple procedures are performed together and when resurfacing procedures are done at the same time as the lift. The same is true if complications occur such as infection, hematoma, skin loss or compromise, etc.  Facelifts and all surgical procedures for that matter share several possible complications - such as excessive bruising or bleeding (e.g. hematoma), injury to deeper structures, anesthetic complications and so on

Some tightness is to be expected after a facelift procedure. That being said, it generally should not cause issues with talking or eating, and should not cause deep depressions in the skin. Based on the question, it is possible that the underlying Bell's palsy is also contributing. Be sure to discuss any post-operative concerns with the surgeon who performed the procedure.
All the best,

Asymmetry after a facelift for the first few days is normal.  Around 2 weeks, most individuals begin to form collagen lumps in front of the ears, below the jaw, and below the chin.  These are normal and can persist for the first 6-8 weeks though they are usually felt and not seen.  The tightness generally subsides over the first 3 weeks after surgery and normal speech should be possible during the first day after surgery.  I would work closely with your plastic surgeon to make sure you are healing according to timeline he discussed with you prior to your surgery.