I have no dental and a cavity forming?

I have a cavity forming in one of my front teeth, the tooth is only half a tooth as the bottom was done when it grew in from a cavity in the baby tooth.

Because the tooth is in poor condition I can see where the cavity is forming (there is already a small surface whole) and more surface wholes will be forming.

If there anything I can do to prevent this from getting worse?

I brush my teeth twice a day, I use Floss and I use mouth wash. I am not sure what else do to