Small cavity for over a year? please help?

so i have a small cavity on the side of my tooth. iv had it for a year. im scared that i need a root canel. it doesnt hurt or anything. my next appoitment is july 20th. will i make it? it feals kinda weird when i put pressure on it. is there anyway i can make it stop growing? like gargle this sort of mouthwash? please help im soo scared!!!