Worried about sagging jawline?

I've been having a lot of trouble with my sagging jawline lately, so I'm asking this question. Even though my weight hasn't changed much, my jawline seems to have gotten noticeably bigger. I'm wondering if it's simply fat or a sign of aging due to decreased skin elasticity.

I'd like to know if sagging jawline can be more noticeable depending on my face shape or jawbone structure, and if lifestyle habits and posture can influence the formation of sagging jawline. What are the differences between cases that can be improved with home care, massage, or exercise, and cases that require medical treatment? I've been seeing a lot of treatments like Ulthera and Tenthera lately, but I'm wondering if I should consider them!