I know that you are unable to diagnose over the Internet but I am hoping to get peoples opinions.

I am 28 female and am a smoker. I have noticed I have an area of white lines on my bottom gum extending slightly under my tongue. They are not sore and are about the length of 3 teeth.
Thinking back I have had them for a few years now and I don't think they have gotten any bigger.
I have been attending a few different dentists for the last year or so ( root canal, dental implant, fillings) and have had many X-ray and many eyes on my mouth of late.
I am terrified that I have oral cancer.. The more I google the more scared I get even going back to the dentist now scares me in case it is bad news :-(