What are some effective treatments for a double chin?

I am extremely stressed because the skin under my chin has folded, possibly due to my habit of looking down at my smartphone frequently.

Since my double chin stands out every time I take a picture, at some point I started avoiding photos taken by others.

I’ve decided to get a treatment to really lift my double chin. There are so many different types, like injections and radiofrequency devices, so which one should I choose to see the proper results? I want to get rid of my double chin quickly in a short period of time, so if you know of any procedures that can definitely restore my jawline, please recommend them. I can tolerate some pain, so I would be grateful if you could share a method with guaranteed results.