What am I supposed to do?

I know I have cancer. Throat cancer or esophageal cancer.
It is hard to breathe and my voice dropped very badly. My voice s very hoarse .
My doctor thinks it is thyroid problems, but I know ( I actually know it started from smoking and alcohol). It started as a minor itch in the throat like an itching, stabbing pain. My gums grew a painless white flesh-like skin. I tore it off(painlessly). I have some bumps in my gums and under my tongue. My breathing is becoming hard and I find it hard to say some things because of my throat.

My doctor and I met and we done blood tests and ultrasound. The doctors think it is thyroid, but it happened because of smoking and alcohol.

My father is a prejudiced man, and stubborn. He doesn't believe it could be cancer. I am running out of hope.

I wish the doctors would look in my throat in depth.

I blame myself for my condition.

I don't know how to explain to the doctors or how to tell my father without him being angry at me ( he has every right to be ).

I don't know what to do.