What Causes Heavy Vaginal Discharge?

I ve been having vaginal discharge ever since I got my first period, that was 5 years ago (I am 18). Although, recently I read that natural vaginal discharge is good thing as it cleans your vagina. However, since the past two years I ve been having heavy vaginal discharge with the foul odor. It s a thick white gooey substance and it smells like fish. A little stronger than the smell of fish, though. I started drinking coriander water in the morning, on an empty stomach. I d soak 1 tablespoon of coriander in one glass of water, overnight and I would drink it in the morning. I benefited from it a little in the beginning, but the odor never finished. Please provide me of help.