I am 66 years old and I hate the sagging on my neck and jowl area. What treatment do you suggest?

Tightening the platysma mucle, removing excess fat as well as skin can only be accomplished by a full facelift.

At 66 years young, you can almost certainly benefit from a facelift to tighten your neck and jowls.  Concentrate on finding an experienced plastic surgeon in your area who does natural work.  You probably also will need your eyelids done unless they have been done before.  Don't get talked into any fat injections though.  They are a waste of money.

Based on your description, as reasonable approach would be a face and neck lift that would address the jowling and neck laxity that you describe. Skin excess would be addressed during this procedure as well. The addition of fat grafting to the midface often helps to improve overall facial youthfulness.

Lower face-neck lift for 66 year old

From your limited description it appears that you would benefit from a
lower face-neck lift. In my practice a patient with your presentation get a
significant rejuvenating effect from this procedure with rather rapid recovery.
Seek out an experienced and talented surgeon for in person consultation. Review
the surgeon’s before and after photos to assess the type of results that you
might expect for yourself.

Based on your age and the areas that you mentioned, I think you would be a good candidate for a face and neck lift.  I would love to help you with it if you are interested in traveling to Austin.