My tooth is sensitive; please give me some advice on how to fix it.

A few months ago, I started experiencing tooth sensitivity in the innermost molar on the right side.

Usually it's okay, but when I chew certain foods, I feel a tingling sensation that becomes so sharp I can't chew.

Mostly kimchi? I experience these symptoms when I eat it;;

I went to the local dentist for a cleaning, and they said my teeth are worn down a lot. In this case, should I get crowns?

Because of this tingling sensation, I now find it more comfortable to chew only on the left side.

I'm scared that I might need a root canal treatment..

What should I do?