Double chin and neck fat removal
A double chin can be caused from excess skin or fat in the neck which is impossible to tell from the photo taken from across the room. A full set of photos are required before giving any opinion. A neck lift or liposuction in the neck may be required depending upon the presenting issues.
Options to treat double chin
Close up photos of your face and neck or an examination would be needed to give you the best advice. It does appear from the photo you provided that liposuction under your chin would be helpful. The exam would determine whether any other procedures would help or not.
Based on this one picture, it appears that there may be a significant skin issue and not just fat alone that is causing your double chin. An examination would clarify that issue. I suspect that more weight loss will not make any difference in the shape of your neck. Whether this will need correction by liposuction alone or a submentoplasty procedure is best determined by a physical examination.