What Causes Thick,foul Smelling Vaginal Discharge?

Hello...I have had a few odd symtoms that go away and come back intermittently throughout the past few months. I have recently had a diet change and am eating a lot of sugar because of a medication I take. My symtoms are thick discolored discharge, fishy and foul in smell, a portruding cervix, and the discharge squirts out when I push to go to the bathroom. It smells horrible after sex, so I don't have it anymore. It sounds like BV to me, so I take B vitamins and try to cut down my sugar intake. I can not get rid of it, and I don't know what to do!! Please make some reccomendations...Thank you!