What is a method at home i can do for cavities to prevent further damage?

NO: Tooth denay is caused by bacteria and once it has started the only way to treat decay is to have the decay removed and the tooth filled. Decay will continue to progress and get bigger and deepeer until it is treated so the sooner you can get treatment the better. See a dentist!

To a point: Dental cavities are caused by acid that is produced by bacteria...They make acid out of carbohydrates. If you rinse vigouously with water and bicarbonate (sodium bicarbonate) of soda or chew and swish an anacid tablet, the acid can be neutralized. However, this is not meant to be long term 'fix'. Your tooth needs to be evaluated and repaired by a professional.