Gum graft after orthodontic treatment?

Has anyone experienced gum exposure during orthodontic treatment and tried gum grafting?

I'm in that situation right now, but still, the gum area that was exposed is swelling quite a bit.

But at the hospital, they said I might also need a gum transplant, so I'm really scared ㅠㅠ

If anyone has tried it, I'm very curious whether it's a simple surgery... if it doesn't hurt, and how the recovery isㅠㅠ

I'm really scared because I haven't done it before ㅠ