Early 30s, have very loose/ thick skin on my neck at the back of my neck/jaw. What’s the best surgical option for me?

The photographs demonstrate significant fat deposits located both above and below the platysma muscle in your neck. Since you've already had liposuction, most of the fat is probably located below the muscle which is going to require and neck lift procedure. This also includes a platysma plasty to significantly improve the jawline. Your BMI should also be less than 32 to be a good candidate for this surgical procedure