About what feels like a lump under your chin...

I'm thinking about surgery because of my square jaw. When I decide to have surgery, all my nerves go to my jaw. It's also scary. But I can feel something like a big lump on both sides of the area from under my chin to my neck. I'm really worried. It's not like it's painful or getting bigger or anything like that... I wonder if it happens to everyone... Now that I've decided to have surgery, I'm worried about every single thing. The area under the chin on one side can only be touched when the chin is bent deeply, but on the other side, the area connected to the neck by the muscles under the chin can be easily touched even without bending down too much, so I wonder if it could be dangerous if touched during the surgery... Ugh~ I'm just full of worries.